You can check out Dropbox at their site, and download a Windows, Mac, or Linux client.
Sync and Back Up Files using Dropbox
We recently started testing a freeware application and web service called Dropbox. Dropbox instantly backs up files you place in a designated folder to the Dropbox server. Whenever you modify a file, it will update the copy on the server. Dropbox also does revision history, so you can recover older versions should you lose something.
Another free service to check out is Mozy Home, an online backup service that allows you store 2GB with auto-incremental scheduled backups.
Yes, we are familiar with it. But it is a backup, not a sync service, which makes it a bit different in practices. Also, it doesn’t have a Linux client, so it wouldn’t work on all of our systems. We are most fond of services that have versions that work on any computer. We may end up mentioning Mozy in an article. We actually thought we had at some point.