BlackDog is a a USB powerd linux server that’s about the size of an iPod mini. Plug it in to a host computer’s USB port and it takes over the monitor, keyboard, mouse, and network connections. Remove it and everything on the host is returned to its original state. It’s powered by a 400Mhz PPC running Debian with 64M RAM and 256 or 512 MB of flash memory. Cost? $240 for the 512M version.