Wuala, the innovative P2P social grid storage coming out of Switzerland, is doing a sneak preview of its public beta from now until Monday evening, after which it will close until the full launch on August 14. It’s worth checking this out before the window closes as I’m betting Wuala is pretty much unlike any online storage service you’ve seen.

The public beta in August will carry a twist. Till now you have to download a Mac, PC or Linux client to access the service. But from the 14th, users will be able to simply click on a button on the site to start the service (it’s a Java app). That’s it. No software installation and no user account required. You can use it for file backup, photo and video sharing, or making files available publicly. Wuala competes in the storage space with Xdrive or Box.net.

So far they have about 30,000 users globally, sharing millions of files. Interestingly, one of them is the Swiss Television Network, which, instead of streaming shows from a site in Flash, just distributes the whole shows as files onto Wuala’s service – which also streams the video direct, no downloading.

The underlying core tech behind Wuala is based on research conducted at ETH Zurich (the Swiss Federal Institute of Technology). The files are held in tiny encrypted pieces distributed across the “Wuala Grid” of users, and mirrored on Wuala’s servers – so you don’t have to rely on other users being online to access your data. Users start with 1 GB of storage but can get as much as they want, either by trading idle disk space or by buying additional storage. You start off with 1GB of free storage, and then if you want more, you can make more space available on your own hard drive for other Wuala members. But users don’t have to trade storage – you can buy extra storage, like 100GB is 100 Euros. All files are encrypted on the user’s computer and the user chooses who gets access to which folder. No one else – including Wuala – gets to see the files. None of the fragments of files from other people stored on your computer are executable. Unlike Web storage, you can drag and drop files into Wuala on or offline.

Now, with any storage there is the issue of copyrighted and controversial material being uploaded. However, Wuala is not like an ‘in the wild’ bit torrent or file-sharing service – anything like shared publicly gets removed. Though there is a slight issue: private groups are encrypted, but then that stuff gets shared all over, whatever service it is.

TechCrunch UK broke the story about Wuala back in October last year. Dominik Grolimund, CEO, previously founded a software company in Switzerland, but exited from that so Wuala is self-funded right now.

Users of peer-to-peer storage service Wuala can now invite others to join private alpha testing. Put your name down on the InviteShare list for Wuala to get your own access to the service. And if you’re already a proud Wuala user, head over there to spread the wealth.

Wuala, which we covered here in October, allows users to backup data on each other’s computers. Storage availability starts off at 1GB and grows from there as you provide more of your own hard drive to others (and leave your computer powered on for long enough each day). Soon you will be able to trade space on your hard drive for the same amount of backup space elsewhere, or get an additional gigabyte of storage for every friend you invite to Wuala. The data you squirrel away on strangers’ computers is encrypted and broken up into 500 pieces spread out over that many machines.

One of the favorite things I like to hear from developers when some horrible and embarrassing bug manifests itself is “It’s a feature not a bug.” It’s a joke of course, but it’s unlikely Microsoft developers will be doing any joking around as they try to control the damage from a recent bug that autodeletes users’ most important files.

Microsoft FolderShare allows users to back up and synchronize files across multiple machines. Generally only important files, that need to be accessed regularly, are synchronized. The bug, which Microsoft told users about via an email and notice on the site after they fixed it on December 7, auto-deleted files that contain special characters (such as accents, trademark signs, etc.)

“Do NOT delete files from your FolderShare Trash folder until you are certain that you were not affected by this problem” Microsoft said to users. The bug occurred beginning on December 3 and was fixed on December 7.

This isn’t hugely damaging (most files were unaffected), but Foldershare is under significant competitive pressure from a horde of startups like Switzerland-based Wuala. Losing user trust from hiccups like this will only help those startups get market share. Perhaps, like FolderShare, Microsoft will eventually buy one or more of them, too.

Okay, I’ve been sitting on these too long. At the Web 2.0 conference, I met a young Swiss entrepreneur named Dominik Grolimund, who is the CEO of a peer-to-peer storage application called Wuala. TechCrunch UK covered it here. The first 1,000 TechCrunch readers who sign up will get into the alpha. (Enter code “techcrunch”).

Wuala is a P2P competitor to Xdrive, MediaMax or Box.net.. You start off with 1GB of free storage, and then if you want more, you need to make more space available on your own hard drive for other Wuala members. (The amount of extra storage you get also depends on what percentage of time your computer is online). The files you want to store get broken up into 500 encrypted fragments, each of which get stored on another Wuala member’s computer. In this respect, it works a lot like a RAID storage system with redundancy built in. But instead of being stored on a central server, all your files are distributed across other peer computers. You drag and drop files into folders just like on your desktop. You can also stream videos or music to a computer with Wuala installed on it. But, unlike BitTorrent (or Oink, for that matter), the service is more about storing your own files than sharing them with a massive amount of other people. Although, I’m sure people will figure out how to use it as darknet service. Thankfully, none of the files stored on your computer are executable.