Sugarsync is the most sophisticated online backup+sync, but also has very buggy software client that frequently has problems syncing and many times causes data loss.

By using SugarSync you grant a worldwide, non-exclusive, PERPETUAL, royalty-free license of your files. Even after closing your account they retain the rights to your data!

Check terms of use at https://www.sugarsync.com/terms.html section “11.Submissions” for perpetual license grant and section “13.Service Limitations” for no warrant of data availability and support.

Also you may research at http://getsatisfaction.com/sharpcast before trusting your files to SugarSync.

Their client won’t backup external drives. They promised me at the beginning of this year that it would be added by fall. What good is a service that can only back up some of your files?