Still in beta, Pol-Online's Mathusalem is an open-source Mac utility that resides in your System Preferences and offers scheduled backups of selected folders to local drives, iDisk, WebDAV, AFP, FTP, SFTP or Amazon S3. You can chose to save your backups as sparse images, compressed .dmg, CPIO or ZIP archives. And since it runs in low-priority mode, Mathusalem doesn't tax your system.

Being beta software, it does have some limitations. As the familiar border of its icon suggests, Mathusalem is designed to work well with and along side Leopard's Time Machine and thus requires Mac OS X 10.5 to run.