If you manage windows servers and don't have Shadow Copies of Shared Folders running, you need to set it up.
In case you don't know, Shadow Copies is a backup feature included with 2003 (and more recent) servers. It functions by taking snapshots of your shares at specified points in time. You can also specify the location that these snapshots live - a $200 usb 1TB hard disk, for example.
You can specify how much disk space to be allocated for your snapshots, and windows will manage that for you - deleting the old snapshots as required. You'll get a TON of snapshots on your backup media, as the snapshots track the changes on a bit level. What this means is that unlike Apple's Time Machine, you don't take a complete copy of each file every time they change.
I have my snapshots set to run twice a day, which is probably pretty conservative. I was concerned about seeing a performance hit - which I really have not noticed.
Now when a user calls requiring a file restore, I don't even flinch. I'm not worried about going and finding the right tape, or having to go run offsite to get the right backup media. It is always just right there. And the restores are as quick as a file copy. No waiting for tapes to rewind, seek, etc. We still have tape backups that we keep offsite, but we never have to use tapes for user file recover requests now.
Another great thing about Shadow Copies, is that if an end user has Vista, or previous windows version (with the shadow copies client) they can do their own restores - without involving the system admins.
Oh yeah, Vista can also run shadow copies so you can keep your local files safe in the same way.