If you are familiar with Symantec Ghost, then you already know what Clonezilla can do for you.
Ghost is a partition copying utility for windows. It geared toward making and restoring complete copies of individual system's hard disks. There is an open-source alternative called Partimage. Symantec also offers a corporate edition designed to use for cloning multiple machines out over a network. This is exactly what Clonezilla does for free - and it is open source.
Ghost has a nice GUI, and a nice polished package. Clonezilla is all text (but menu driven), and harder to use. But it also has many more options, and supports more file systems - such as the kind typically used by Linux.
By itself, Clonezilla requires a server backend. Setting this up is probably more work than it is worth for most small/medium business IT folks. However there is an excellent Clonezilla Live disk, which runs all by itself. I use Clonezilla live for almost all my partition work. Clonezilla actually uses several open-source utilities (including Partimage), so It can copy and restore partitions to/from external usb disks, firewire disk, smb (windows) shares, just about anything you can think of. You can copy the partitions directly, or to archived images. It is the all in one partition toolkit, except for resizing that is.
I use Clonezilla Live to image multiple machines each week, sometimes up to 20 at a time. On the Clonezilla Live site, they warn that if you are imaging multiple machines, you should use Clonezilla with its DRBL server. From what I've seen, for my needs, Clonzilla Live's performance has been more than adequate.