Clonezilla is a partition or disk clone tool similar to Norton Ghost. It saves and restores only used blocks in hard drive. Two types of Clonezilla are available, Clonezilla live and Clonezilla SE (Server Edition). Clonezilla live is suitable for single machine backup and restore. While Clonezilla SE is for massive deployment, it can clone many (40 plus) computers simultaneously.
Features of Clonezilla are Free (GPL) Software, Filesystem supported ext2, ext3, ext4, reiserfs, xfs, jfs of GNU/Linux, FAT, NTFS of MS Windows, and HFS+ of Mac OS, Multicast is supported in Clonezilla SE, which is suitable for massively clone. You can also remotely use it to save or restore a bunch of computers if PXE and Wake-on-LAN are supported in your clients.