http://www.bombich.com/ has a lot of software for imaging/ghosting macs, and various programs for managing both labs full of macs and single macs. It's all free, and their Netrestore package is apparently what Apple use to install their own Macs..
Basically, NetRestore and CarbonCopyCloner do the same thing: They let you store a working image of your Mac's harddrive. Netrestore works with DMG files and is designed to enable you to store images on the network, and CarbonCopyCloner is designed so that you store the images on another harddrive or DVD.
CCC also apparently has the option to automatically perform a backup at a scheduled time, or when a device is plugged in.