Just came over two free online storage accounts hosted somewhere on the net.
The first one is AMD Live! Media Vault (seems like AMD Live! promotion) which offers 25GB of free disk space. Upload file siz e is limited to 25MB and you can't download more than 1GB per month. Oh, and you can share your files. Downside? The only downsize lies in the fact that you have to use custom file manager, IOW you can't upload/download files programmatically (at least at first glance).
The other one is XDrive, which is not a newcomer and offers 5GB for free. It features various ways of file uploading and no apparent limitations on both upload and download. It also features backup software (why you need backups) which is a very good thing and desktop software that integrates xdrive into windows explorer. To create an account you have to sign in with AOL/AIM credentials.
As you see both offers are worth to check them out. I know I'll check XDrive because it might work from within SyncBackSE backup utility I use.
UPDATE 21.9.: These comments don't look very good at all for XDrive.