Box is a cloud-based file sharing application similar to DropBox except that it offers collaboration features. Targeted to the enterprise, with high profile customers such as DELL or MTV and over 6 million users, Box.net has been around since 2005 and is now available on various desktop and mobile OS.
Today, Box is launching on the HP TouchPad tablet with a great offer: the free personal version provides 50 GB of free cloud storage and up to 3 users (iCloud offers only 5 GB for free). The Business option costs $15 per user per month with additional features. Check Box.net website for more info about the pricing.
I have not tried the application yet but since it is free and available on Android (smartphone) and iOS (iPhone and iPad), you can play with it to see if you like it.