Box.net has been around for quite a while, but is still one of our favorite places to store documents online. Thanks to its integration with numerous online services, including Gmail, Zoho, picnick, and Scribd, box.net can not only store all your documents, but can also function as the hub of your virtual office.

One other nice feature of box.net is that you can share your files and folders with 'collaborators,' which makes it a good service to exchange files within a small business or among friends.

The storage limit for the free accounts is 1GB, which is plenty if you mostly exchange text documents or spreadsheets. Paid accounts start at $7.95 a month and include more advanced features, including 5GB of storage, a versioning system, mobile access, and 24/7 phone support.

Live Mesh

The online storage component of Live Mesh is only one part of Micorsoft's latest venture into cloud computing, but it is also one of its most compelling features at this point. Live Mesh gives you 5GB of online storage and an online desktop that looks a lot like Windows Vista. You can upload any type of file to Live Mesh, but you cannot edit any of your files through the online desktop. In the future, though, we expect Microsoft to start adding more of these features.

One of the main reasons we like Mesh is because it constantly watches for changes in the folders you are synchronizing to it and updates them automatically. In addition, you can share folders with friends, allowing you to collaborate on projects.

Live Mesh works on both Windows PCs and Macs.

DropBox

Few online storage services integrate with your desktop as well as DropBox, which only recently opened up to the public after an extensive beta test. While you do have to install a small program on your machine to run DropBox, it is well worth it. Besides setting up a folder on your machine, which automatically syncs with DropBox, you can also set DropBox up to then sync that folder with other machines, similar to Live Mesh. DropBox lets you upload any type of file, as long as it is smaller than 350MB. DropBox uses Amazon's S3 service as its storage solution and provides its users with 2GB of free storage. For $9.99 a month or $99.99 a year, you can buy 50GB of storage.

One of our favorite features of DropBox is that it preserves every revision of every file. You can also easily share folders with your friends or colleagues.

DropBox supports Windows XP and Vista, Mac OSX, and Linux.

Oosah

Oosah's main selling point is simple: you get a whopping 1 terabyte of storage for media files. One restriction of Oosah is that you can't use it for text documents, spreadsheets, or presentations, which seems a bit weird, given that those types of files are generally small.

One interesting aspect of Oosah is that it accepts RAW image files from most camera manufacturers, though it automatically converts them into JPGs. You can also connect to your Picasa, Flickr, Facebook, and YouTube accounts and view your images and videos from those services in one central place. Oosah also gives you Media RSS feeds and even a podcast feed for your audio files.

While we love Oosah for its general ease of use, the one aspect we really did not enjoy was the fact that uploading files seems to be unnecessarily hard. Oosah does not provide any desktop clients and while you can use the web based uploader to select multiple files, uploading multiple directories at a time is not an option.

JungleDisk

JungleDisk is the only service in this list that is not available for free - and technically, it is not even an online storage service. Instead, it provides a frontend to Amazon's S3 storage service. JungleDisk costs $20 and after that, you pay Amazon for the storage and transfer of your files. JungleDisk also lets you map your Amazon S3 storage space as a network drive on your computer, so that you can just drag and drop files back and forth between your online storage and your local desktop.

JungleDisk is available for Windows, Mac OSX, and Linux.

Other Services

Online storage is a competitive market. The best services integrate fully with your desktop and allow you to effortlessly upload and download files. They also provide you with an online desktop to access files from any computers and are stable and dependable. A service that does not fulfill these basic requirements is going to have a hard time convincing users to use and trust it.

There are, of course, a large number of other online storage services that we did not include in this list. BOXSTr, for example, is a great application, but it constantly bothers you with ads and attempts to sell you their premium service. AOL's Xdrive is a great service, too, but we have heard too many rumors that AOL is trying to sell the service or that they will simply close it to be able to recommend it anymore.

The one company that is suspiciously missing from this list is Google. While you can upload your documents to Google Docs, the company that has made cloud computing a household name does not have a dedicated file storage service. While rumors about the existence of a 'GDrive' have regularly appeared in the tech blogosphere over the last few year, users still have to rely on hacks like the GMail Drive shell extension to store their files on Google's servers.

What Did We Miss?

Do you have a favorite service that we did not list? Let us know in the comments.

Logo courtesy of Flickr user blakespot.

While Wuala will happily sell you additional storage space (from $25 a year for 10GB to $1000 for 1TB), you can also trade your own local disk space for cloud storage space. If you share 5GB of space on your local drive, you will get an additional 5GB of online storage. Given how cheap hard disks have become, this seems like a fair trade-off. Users who share their local hard disk space can also turn off advertising on Wuala.

Wuala's client basically looks like a local folder and you can decide if you want to share any of your files stored on Wuala with either your friends or a group of users.

Encryption: The Good and the Bad

Even with the strong encryption Wuala uses, though, the fact that some information is going to be stored on machines outside of even Wuala's control is not going to sit well with a lot of people. While most private users can probably live with these risks (which are inherent in any cloud storage solution), businesses will probably stay very far away from Wuala.

There is also the question of how people will use Wuala - after all, the service provides almost unlimited and strongly encrypted storage. As Wuala has little control over what is shared on the network, Wuala might turn out to be a haven for rather unsavory activities. But then, the same can probably be said for most other cloud storage services as well.

Where's the Money?

The cloud storage market is highly competitive, but so far, no clear front-runner has emerged. Wuala's competitors include Box.net, Dropbox, Mozy, as well as Apple's Mobile Me and Microsoft's various online storage services, including SkyDrive and Mesh. There are also various software solutions to make backing up to Amazon's S3 more consumer friendly. All of these have different business models and feature sets, but Wuala's simplicity and P2P sharing approach will make it very competitive.

The service, which offers a free 45 day trial, costs $49.99/year for 10GB of storage with plans running up to $249.99/year. The company is running a special 50% off the first year promotion, but 200 ReadWriteWeb readers can have the promotional price extended to two years by clicking this link.

SugarSync provides both a PC and Mac client, as well as mobile clients for the Blackberry and Windows Mobile and a browser-based application.

How Does It Perform?

SugarSync is the product of nearly four years of work by the crew at Sharpcast, and the result is quite nice. It's an easy to use system that can free your data from a single, physical location. It has some nice features, such as the ability to share photos with friends, or the ability to lock certain versions of files online so that even if they're updated locally you still have a backup of the original. It also has some things we wish it did better, such as automatic file versioning, which is absent in this release.

In January, we said that Sharpcast reminded us of Feedburner, "in that it wants to become the leading platform for a new type of media service that only came into being in the Internet age." In Feedburner's case that service was RSS, whereas for Sharpcast that technology is file syncing.

Unlike Feedburner, though, SugarSync is entering a slightly more crowded space. They face competition from BeInSync, Windows Live FolderShare, and the currently in beta Y Combinator startup Dropbox. Even so, SugarSync comes to the table with a very nice product that is super easy to use and quite polished (it should be after 4 years!), so we still expect that our earlier prediction that it could be a future acquisition target to hold true.

Have you tried SugarSync? What about any of its competitors? Which do you like better? Let us know in the comments below.

Note: An earlier version of this article erroneously stated that SugarSync costs $49.99 per month for the 10GB package. That is incorrect. $49.99 is the yearly price at that storage level.