LinuxDevices.com has story on the recently announced Cyclades TS100 device server, a tiny blue box containing a Motorola MPC885T dual core (a 32bit PowerPC and a RISC processor on the same chip). The TS100 also has 16MB of SDRAM, a 4MB Flash disk, a 10/100 Ethernet port, RS-232, and RS-485 ports. And, here's the best part: it runs Linux so it's easy to hack the code to meet your needs. They may call it a "device server" but I call it ideal for controlling a small robot. Just add some RS-485 based sensors and an RS-232 servo controller and you're all set to go.