Online restaurant reservation site OpenTable has hit a milestone today, seating one million diners via its mobile apps. And the site says that based on an estimation of a $50 average check per diner, OpenTable believes that diners using its mobile applications have generated more than $50 million in revenue for its restaurant partners.

OpenTable allows diners to find and book reservations at more than 11,000 different restaurants in multiple countries via mobile applications for the iPhone, Palm, Blackberry and Android. Other smartphone users can book reservations through OpenTable’s mobile-optimized Web site.

Back when OpenTable launched on the iPhone in November of last year, one of the very first comments we got on the story was from a gent named Chris. “Unless it’s on Android, it’s useless,” it read.

Good news, Chris! OpenTable is no longer useless to you. This morning, the online restaurant reservation service launched their app onto the Android Market.

As with both their web service and the applications available on other platforms, the OpenTable Android app serves as a means of checking for and reserving tables without having to dial any numbers, wait on hold, or strike up a conversation with a hostess.

As Erick pointed out yesterday, IPO registrations are up. But even if all of these companies go out, does this mean VCs are out of the no liquidity woods? Hardly.

Sure everyone brings up LinkedIn and Facebook as the potentially huge homerun IPOs in the wings, but a lot of the companies queuing up look more like OpenTable.

The reservation Web site deserves props for making it out in a tricky time— the weekend it was picking its bankers one declared bankruptcy and another sold itself to a competitor. And yes, the price has impressively stayed above the $20 opening. But take a closer look at the deal: Only three million shares were floated to the public. No wonder the price has held– hardly anyone is in the stock. With a whopping 18 million still owned by insiders and investors, OpenTable looks more like a private company that just did another round of funding than a public company.

Another small sign that the worst of the recession may be behind us: IPO registrations are clawing their way back from the shadow of the valley of death (also known as the first quarter if 2009, when there were zero IPOs registered with the SEC). So far in July and August alone there have been 14 IPOs, as many as in the previous three quarters combined. These numbers and the chart above are based on the number of IPO filings tracked by Hoovers as of yesterday. Renaissance Capital counts 16 IPO registrations in July and August, and if you look on the SEC’s Edgar site it looks like a few more filed today.

Registering for an IPO doesn’t mean that the company is actually going to go through with it, but the volume of filings is a good confidence index for startups.

After four quarters in which venture-backed IPOs have been dead in the water, a handful finally poked their heads up in the second quarter. The National Venture Capital Association counted five IPOs during the quarter, including DigitalGlobe ($279 million raised), SolarWinds ($152 million), and OpenTable ($60 million). A total of $721 million was raised. Just for a little context, two years ago during the same period, there were 25 IPOs which raised $4.15 billion.

So don’t call it a comeback just yet. But any activity is a sign of hope. And this was the most active period since the fourth quarter of 2007. Will it keep building, or will IPO candidates duck their heads back under water?

In the online reservation space, you probably know about OpenTable. The restaurant reservation service’s IPO in a time of drought for IPOs, made big headlines. Now imagine OpenTable for just about everything besides restaurants. That’s BookFresh.

Who might need such a service? A lot more services and individuals than you may realize. While most services have some sort of scheduling system, many aren’t optimized, and can’t adapt on the fly to openings/changes. Massage therapists, dentists, doctors are all perfect examples of who could use such a system, founder Ryan Donahue tells us. He notes that health and beauty has been a particularly hot area.

He knows that because the service has actually been around for a little while, but it was formerly know as HourTown. But BookFresh is a much better name for the service because, “appointments are much like produce items in a grocery store, it’s a perishable thing,” Donahue says.

Is the IPO drought over? Not quite. But OpenTable’s successful IPO today will give tech startups and VCs a sign of hope that you can still go public eventually if you have a real business. On a day when the Nasdaq is down 2 percent, OpenTable is up 40 45 percent from its offering price of $20 (which itself kept moving up from $12 to $14 initially). The stock opened at $24, and was trading at around $28 $29 last time I checked. With 21.6 million shares outstanding, that gives OpenTable a market capitalization of $605 $626 million on its first day of trading. (The company itself cleared $60 million in the offering). Update: The stock closed at $31.89, up 59 percent from the offering price, giving the company a market cap of $689 million at the end of the trading day.

This is an extremely healthy IPO. Opentable is not a blowout Internet company. But it is a solid Internet company that matters. It pulled in $55.8 million in revenues last year and a net loss of $1 million (largely due to expansion-related costs). In the first quarter of 2009, it managed to turn a net profit of $366,000 on revenues of $16 million. (For a deeper financial analysis, see this earlier post).

Why is it that you can book a table at a fancy restaurant through OpenTable, but you can’t book the bar for a corporate party? That is the question that a startup in New York City called Pogby is trying to answer. Barely in beta, Pogby is an event booking service founded by Joshua Gooch, who used to run JetBlue’s Website and helped build its TrueBlue customer loyalty program. Pogby aims to become the OpenTable of events, where corporate event planners and others can find and book venues for parties.

The site is really not much more than an online demo right now, with only a half dozen venues in New York City on the site. But Gooch and his VP of sales Duane Lawrence plan to sign up 50 to 100 restaurants, bars, and other event spaces in short order. They are focusing on New York City to prove the concept. (This is really early stage—the company is still looking for seed funding). Each venue on Pogby gets its own page with pictures for each available event space, along with a calendar showing availability and a booking engine. Gooch knows a lot about reservation systems from his time at JetBlue, and you can see some of the design influences on Pogby.

it’s a fairly simple concept. Find a venue, check pricing and availability, and book online. Pogby plans to charge venues an 8 percent commission fee for any bookings and eventually will introduce a $99/month subscription fee. A typical event can cost $4,000 or more, and event spaces typically go unused 70 percent of the time. So any extra events a restaurant or venue can capture is worth the fees. Why hasn’t anyone done this already?

OpenTable, the online restaurant reservation site that was founded in 1998, is hoping to raise as much as $40 million in an IPO, according to a filing with the SEC (embedded below). The prospectus offers a detailed look at the company’s finances and operations.

Revenues through the nine months ended September 30, 2008 were $41.3 million, a 41 percent increase from the same period in 2007. Revenues through the nine months ended September 30, 2008 were $41.3 million, a 41 percent increase from the same period in 2007. The company makes money from the restaurants, which pay both subscription fees (54 percent of revenues) and reservation fees for each diner that shows up through the system (42 percent of revenues). It also makes a small amount on installation fees (4 percent of revenues).

The company lost 149,000 in net income, but turned an operating profit of 261,000. That is a rather slim margin, however, it appears that the company was spending as much as it could to grow and take market share, especially internationally where it is just getting started.

Some of the most useful set of apps on the iPhone are the restaurant apps that tell you what is to eat nearby. There’s UrbanSpoon, Yelp, and LocalEats, among others. But once you find a restaurant, you still have to call to make a reservation. Now, you no longer have to use up those minutes. Online reservation service OpenTable released an iPhone app today that lets you not only find nearby restaurants, but book a table as well. You don’t have to call and wait on hold. The app uses OpenTable’s online reservation system to book and confirm a table. It will even give you directions to the restaurant from wherever you are.

You are shown only nearby restaurants, and cannot filter by type of cuisine or refine your search as easily as you can on the Website. But the app is perfectly functional. The key is that it only shows you nearby restaurants that have open tables for the time when you want to eat.