AVG AirSpace cloud sync and backup for Windows enters beta
Once the service exits beta, you'll be able to pay for additional storage. It's also worth knowing that AVG AirSpace (or LiveKive, whichever name the company settles on) functions both as a sync and a backup utility. You can even back up multiple machines' data into the same storage account.
AirSpace also offers a way for you to share uploaded files with your friends and colleagues, just like Dropbox. Unfortunately, at least for the time being, there's only a Windows AirSpace installer -- Mac and Linux aren't supported, and no mobile apps are available either.
Register for AVG AirSpace beta