Imagine a world where you sit at your computer and you never go outside. Where you never see another human being. This is the world that sites like Google and Facebook want you to live in.

Though they’d never admit to such a thing, the reasoning should be obvious: The longer you’re at your computer, the more time you’re spending on their sites. The more time your spending on their sites, the more ads you’re being served. The more ads being served, the more money they are earning. No matter why these sites originally started, or what features they add, that is, quite literally, the bottom line. They’d have us strapped to a chair with our eyes taped open like Alex in A Clockwork Orange, if they could. The only difference is that we’d have a contraption on our arms to allow us to click on the ads being shown every so often.

Thankfully, we don’t quite live in that world yet. And there are a couple factors pushing us the opposite way from that. Mobile devices are the biggest one. But even that is still just a screen. You may not be chained to a desk using it, but as plenty of people with an iPhone will tell you, you may end staring at this screen even more than you do a desktop or laptop monitor throughout a day. But there’s another up and coming factor working against our screen slavery: Location.

As a blackberry user, I generally feel a little left out of of the location-based apps world. FourSquare only provides a mobile site for BlackBerry users (but has an Android app). BrightKite has an innovative BlackBerry app, but it’s not nearly as feature-rich as its sister iPhone app. Today, location-based social network Loopt is making a major upgrade to its BlackBerry app.

The new version of the app has one significant feature that even trumps the iPhone app: background location updating. So even when the app isn’t running, your location will be updated in real-time in the background. Loopt’s new app also pulls in local content about restaurants, bars and events from Zagat, Citysearch and the Loopt community, creating a local search engine within the app.And you can rate places you visit as well from the app.

In the Steven Spielberg movie Minority Report (yes, I make some reference to it about once a week), there’s a scene in which John Anderton (Tom Cruise’s character) is walking through an urban retail center and his eyes are getting scanned as he moves, which is serving up custom greetings and deals from retailers. It’s both creepy and cool. But that movie is set in 2054, we’re not there yet. But AT&T had a demo at its Tech Showcase today that is inching closer to that.

As you can see in the video below, the idea behind AT&T’s system is that you can walk around a city with a phone in your pocket and get alerted when a nearby retailer has a deal for you. Users of Foursquare and soon Loopt will recognize this concept, but AT&T’s idea is a bit different. By using AT&T’s network as the bridge to be constantly updating your location (assuming, of course, you opt-in to such a feature), these retailers are able to push these coupons to your phone via SMS. Currently, something like Foursquare requires that you “check-in” to a place to see that there is a deal there or nearby.

When Loopt launched in 2006 it was ahead of a curve that is just starting to be recognized: Location. Now, with services like Foursquare, Gowalla, Brightkite, and even Twitter fueling the location-based services frenzy, Loopt realized that it needed to shift its strategy a bit. Enter Pulse, a new feature launching today.

Previously, Loopt was more of a passive service — you started it up on some device and it kept track of where you were. Other users could see where you were if they opened the app too, but generally it wasn’t about pinging your friends to let them know where you are and what you were doing. But Pulse makes Loopt much more of an active service. It recommends hot places, hot events, and lets you know what your friends are up to.

Foursquare and Loopt have put location-based social networks on the map, and have potentially created a viable business model as well. Now there’s a new kid on the block, called Stalqer, which best described as a Foursquare on steroids. The iPhone app, which will be free, should hit the app store in the next few hours.

In theory, Stalqer is very similar to Foursquare in that it tracks your and your friends’ locations and broadcasts this information via the application and through push notifications. But one of the key differentiators is the fact that Stalqer updates the location in the background, which Foursquare, and most other apps, don’t do at the moment. This is because the device does not allow third party apps to run in the background. But Stalqer has found a way to record your location without you having to actually open up the application. So how does Stalqer do it?

Last night we broke the news that location-based mobile social network Loopt had acquired GraffitiGeo, a fellow Y Combinator-backed startup that launched only a few months ago. Neither company was willing to comment on the acqusition last night, but earlier today they finally confirmed it and opened up to share some of the logic behind the deal.

GraffitiGeo launched in August, when I described it as a ‘Foursquare meets Yelp, with a dash of augmented reality’. The service invites users to review local restaurants and other venues in a manner that’s similar to Yelp, but encourages them to leave very brief descriptions (or just thumbs up/thumbs down) instead of the longer reviews you’ll find on other sites.

Loopt, the New Enterprise Associates and Sequoia-backed mobile social network, has acquired a relative newcomer to the scene – Y Combinator startup GraffitiGEO. Multiple sources have confirmed the acquisition, although neither company is commenting.

GraffitiGEO, which launched just a couple of months ago, combines mobile social networking with reviews and games. It’s somewhat similar to the surging foursquare, which has stolen some of the oxygen from the first generation mobile social networks like Loopt.

GraffitiGEO is also preparing to launch an augmented reality application that we previewed in August and that we suspect will launch shortly. Both GraffitiGEO apps fill holes in Loopt’s product lineup, so the acquisition makes a lot of sense. Here’s the video of the application that we included in that post:

At TechCrunch, we’ve always been big fans of mobile social networks, particularly on the iPhone. In fact, Loopt, one of the first location-based iPhone apps and social networks to gain popularity, was offered a feature, called Mix, that acts as a social compass that allows people to connect with and learn about others around them. Mix turned out to be such a popular feature that Loopt is breaking the feature out into its own free iPhone app.

Loopt is basically a social-mapping app that allows you to discover the world around you on your mobile phone. Mix was the part of the app that let you meet new people (who also have the app) nearby. You see a list of people, profiles/interests, their latest status, ranked by their approximate distance to you and can message the people who you find compelling. While Mix can be used for any type of connection with users, Loopt’s co-founder and CEO Sam Altman says the feature is primarily used for dating and love connections.

A location-based social network is not going to truly take off on the iPhone until it can run in the background. You know it, I know it, and even Loopt, which makes such an app, knows it. That’s why they’ve done something about it.

Beginning today, Loopt is rolling out a trial for background location on the iPhone. Yes, you read that right.

If you’ve been following the iPhone at all over the past couple of years, you’re undoubtedly asking yourself how this is possible, since the device does not allow third party apps to run in the background. Has Apple changed its mind about background apps? Not yet. Instead, Loopt is partnering with other companies in the mobile industry for what it’s calling “Always-On Location Service.”

Loopt was the first location-based iPhone app to get a lot of buzz. It’s a social network that lets you keep track of where your friends are with the help of the iPhone’s GPS. Since it launched in the App Store on day 1 in July of last year, several other competitors have come along including Google with its Latitude service (though it’s not yet available on the iPhone). Now Loopt appears ready to strike back with Loopt 2.0.

The screenshot we received appears to show what Loopt is going for with this new version. The second button in the toolbar is now “Places,” something which didn’t exist before. A source close to the company says this is a big part of the new version. We hear this could help the company offer more monetizable features, such as coupons.

In the nascent world of mobile social networking, there are the big dogs (Facebook and MySpace) and everyone who wants to be a big dog. Two of the puppies just got bigger. Limbo is buying Brightkite, which all the tech kids are raving about, in a nearly all-stock transaction. It will change its name to Brightkite in a re-branding move, and gain Brightkite’s engineering team and product smarts. Limbo CEO Jonathon Linner will remain as CEO, while Brightkite founders Martin May and Brady Becker will take over product management and design.

Meanwhile, Limbo brings a lot of cash to the table, having just raised a previously undisclosed $9 million round of financing in January, 2009. Nexit Ventrures was the lead, and existing investors Azure Capital, Draper Fisher Jurvetson, and New Enterprise Associates also participated. Brightkite, meanwhile, started out as a TechStars startup and was funded with just $1 million in angel money.

Just a housekeeping item: the ridiculous patent infringement lawsuit brought against us and mobile social network Loopt (details here and here) by Earthcomber is history. The company walked away from the lawsuit.

We criticized being included in the lawsuit because we are nothing more than a search filter on Loopt. And the Earthcomber founder appeared to include us out of spite for not giving them as much press as they wanted. From my earlier post:

I called Earthcomber President Jim Brady this morning to verify the lawsuit. At first he wouldn’t answer – all he did was try to explain how he’s been wronged by Loopt. When pressed he did confirm that the lawsuit was filed, but quickly added that he didn’t really mean to press it with us. He wants to go to court with Loopt, but is willing to quickly work something out with us to make this go away, he told me, hinting that he’d like to partner with us. He also said he’s been desperately trying to get me on the phone but hasn’t been able to, so he decided to sue us instead.

Mobile social network Loopt goes live on three AT&T phones today, which was the last major carrier holdout. Loopt is now available in the U.S. on Sprint, Verizon, Metro PCS, T-Mobile and Boost. The service is free for a year and then a $4/month fee kicks in.

You can get Loopt for free on the iPhone (and there is a TechCrunch version), the Blackberry and Android as well.

We’re big believers that mobile is the future of social networking. Loopt and a handful of other brave startups are pushing the envelope on mobile social networks while the big guys, Facebook and MySpace, sit on the sidelines.

A big reason they’re hesitant – privacy concerns. Both companies have had their run ins with the press and state attorneys general. Mobile social network is all about location, and finding people around you. That’s not where Facebook and MySpace want to go right now.

Loopt is in the news today. In addition to getting a nice surge in iPhone downloads after being featured in an Apple TV commercial, we’ve heard that they’ve hired investment bank Allen & Co. to represent them in a sale or financing transaction.

A sale in this economic environment is extremely unlikely, so we’re guessing they’re looking to add to the $13.3 million they’ve already raised from Sequoia Capital and New Enterprise Associates. The valuation on this round is likely to be north of $250 million.

Allen & Co. Managing Director Dave Wehner is the guy pitching the deal, say our sources. He’s tends to get results – representing Bebo in their $850 million sale to AOL, Powerset in their $100 millionish sale to Microsoft and (we believe) Ning in their half billion dollar valuation financing round. Among others.

Facebook and MySpace have great mobile apps. At least, they’re great if you’re satisfied with a subset of the features you get on their normal websites. But they don’t yet take advantage of location/presence features on the iPhone and other platforms. We said this summer that they ignore location at their peril, and we still believe it.

Loopt, one of a handful of location-aware iPhone social networks (and the one we are partnered with), is currently (meaning over the recent period, undefined by Apple) the 20th most popular free iPhone application, and is being downloaded more often than both Facebook and MySpace. Facebook is no. 25, and MySpace is no. 43. This is despite the fact that MySpace and Facebook heavily promote their iPhone apps to their 100 million plus users. Loopt doesn’t have that deep base of existing users to market to. All time, Loopt is the fourth most popular iPhone social networks after Facebook, MySpace and AIM.

We’ve had serious legal threats five times in the past, from YouTube, Marvel, Rivals, Mediascrape and my personal favorite, Richard Figueroa. None of those threats went to court because all of them were absurd, and we don’t back down under any circumstances (unless we’re in the wrong, which we never were).

But today, based on the calls I’ve received from CNET and the San Jose Mercury News, we’ve actually been sued. Earthcomber, the holder of a very shaky mobile patent, first sued Loopt last week, and yesterday added us in an amended complaint. They didn’t even bother with making nasty threats before they filed the complaint. They just sent it into the court and started making calls to the press.

A scantly known startup out of Chicago called Earthcomber has filed a rather absurd patent infringement suit against Loopt, a location-based social network with a substantially higher profile in the Valley and elsewhere.

The suit claims that Loopt has infringed an Earthcomber patent, filed in June 2003 and issued in July 2006, that outlines “a system and method for locating and notifying a user of a person, place or thing having attributes matching the user’s stated preferences.”

Here at TechCrunch we’re big believers in mobile social networks. In February I wrote about how the iPhone is the perfect ecosystem to have it’s own social network (awesome device and software, location aware, elitist users). And in April I showed a teaser of an upcoming social network from Loopt that did everything I had asked for: iPhone only to start, location aware so that you could meet new people around you.

Loopt has now launched all of those features, and they’ve built a special version of the service just for TechCrunch. Once you’ve added the application to your iPhone you can see where your friends are and what they are up to. And you can also meet TechCrunch Loopt members who are near you even if they aren’t your friend yet.

Sign up here, or do a search for LooptTC on iTunes (links to iTunes apps currently don’t work).

We’ve been bullish about location-based social networks for quite awhile now, especially since Apple announced that it would open up the iPhone to developers. And with two significant developments in this space just this week (more on that below), we thought it would be a good time to take a step back and look at the options currently available through the Apple App Store.

What makes a “location-based” social network different than a normal one? At least as things stand today, location-based social networks run primarily on smartphones that have the ability to determine a user’s current location, usually by leveraging GPS or cellular tower triangulation. The social network then uses your location to reveal nearby friends and places of interest. See our Location Technologies Primer for additional information.

Currently there are six major location-based social networks available for the iPhone (see our comparison chart). All of them tell you how far away other members are from you, with most focused on helping you find your friends but some designed primarily for discovering strangers. A few of them chart the location of your friends’ on an interactive map (something I actually think all of them should do). They provide a wide range of privacy settings, but all will stop reporting your location when you simply close the application (Apple has yet to release its push notification system that will let these apps constantly report your location in the background). They also vary widely in how precisely they identify the locations of other members, although all but one of them work anywhere in the United States.

After testing this entire batch, I’ve come to the conclusion that none of them is quite ready to achieve mainstream usage. I believe most, if not all, of the following things must happen before location-based social networking becomes the new “killer app”: