Home users familiar with Norton Ghost will find themselves immediately comfortable with Clonezilla. The premise is the same; creating full-disk backups for single machines and large deployment with network backup and restore. It comes in 2 flavors, Clonezilla Live and Clonezilla SE (Server Edition). The Live version will suffice for home and small office users who want daily backups of their work and personal information. The Server Edition, on the other hand, can be deployed across a network and can allow you to clone multiple computers simultaneously.
The software was first created as Clonezilla SE, but it required jumping through various hoops to make it functional; fine if you're deploying it on a network, but way too much work for a single machine. To address this, the Free Software Lab at NCHC combined it with Debian Live to produce Clonezilla Live. Clonezilla Live can be used to clone individual computers using a CD/DVD or USB flash drive. Though the image size is limited by the boot media's storage capacity, this problem can be eliminated by using a network filesystem such as sshfs or samba. It can be run off a CD/DVD, USB, hard drive or PXE.
To use it, download the relevant ISO image from here.
The links are for the image of Clonezilla based on either Debian or Ubuntu, and it does not matter which distribution of Linux you are running. If you wish to run it off a USB drive, download the files and use the guide here to make it ready. If you wish to run it off your hard drive, use the guide here.