Good review – here is the best alternative as of June 2011: SugarSync.
You get 5GB of cloud storage space with the FREE version, but now there is no restriction to the number of computers you can sync/backup (up from 2).
It gives you the ability to upload and sync any folder on your computer.
It is the only service that offers such a broad device and OS support with apps for BlackBerry, Android, iPhone/iPad, Symbian, not to mention your computer!
You can also stream MP3 music files to your smartphone or computer.
Also if you use the below referral code you get a bonus 500MB extra on top of your Free 5GB!
https/www.sugarsync.com/referral?rf=tbtp0asbw9pt
Hope this helps someone!