Following, Microsoft Sharepoint, Box.net, and Dropbox, Insync, launched with same selling proposition but with tight Google integration for Gmail, Google account, and Google Apps account holders. "After signing into Google account, Insync runs seamlessly with the OS and in the background. You can drag & drop files or create folders just like you would under Windows Explorer or Mac Finder or like Dropbox. Whenever you add, delete, or edit a file on your desktop, it'll automatically sync to Google Docs and vice versa – in (near) real-time.
Want to try it, wait then, till Santa delievres their server. The opening slots are all full. Until, Santa comes to them, you can use Dropbox, they're open to Welcome you.
More Info: Insync