FOG

Source
FOG is a free alternative to products like Symantec’s Ghost, which, while being a very good product, can be too expensive for small imaging operations. Beyond just imaging, FOG also includes a client-side program, which can communicate with the FOG server and manage various things. For instance, you can remotely install new applications, network printers, scan for viruses, and track user access.
The FOG project began in August 2007, and is maintained by Chuck Syperski and Jian Zhang. As of writing this article, they’re currently working on version 0.27, and have made some significant improvements since I began using their product.
FOG is designed for Linux; it’s designed and tested on Fedora, but it also supports Ubuntu. So any machine you can install Linux on, you can probably use as a FOG server.
FOG’s Sourceforge page, and grab the latest version. Extract it to the /opt directory: