I'd highly recommend BackupPC: Open Source Backup to disk
BackupPC comes with a clever pooling scheme that minimizes disk storage and disk I/O. Identical files across multiple backups of the same or different PCs are stored only once resulting in substantial savings in disk storage and disk I/O.
Not only can it backup files tho, it can also restore them to exactually where they were. Also gives a version history, so you can look at a certain file, then get a history of which backups it was changed... good for finding out when files were deleted.
We have a server setup with it with a 1TB drive. Backups all the servers on our network. We have it set for weekly full backups, and nightly incremental backups, regardless of the server and it's role. After pooling & compression our pool is at 177gb for all 14 of our servers (which are a mix of windows server 2k3 and linux (debian, redhat & trixbox for VoIP)).
It can be a bit to get your head around at first, but there is a brill article over at Back Up Linux And Windows Systems With BackupPC | HowtoForge - Linux Howtos and Tutorials on how to get it setup.
Also, it has an archive feature. You can set it to mirror it's entire pool to another server... aka offsite backups. So it can be set to transfer the current pool. Ok 177gbs is a bit much. But we're lucky to have a 10mb fibre to our school. And the council have complained (yet).