Since the umite has embedded routines which make programming motor drivers, servos, and pings trivial, it is ideally suited for control of small robots. I have designed a robot control board which includes a L293D chip in addition to the micromite (170 version) and provision for connecting servos, a "ping", and a bluetooth module.
The png attachment shows an eagle rendition of the board. The attachment, robot.jpg, shows the board in place on the Actobiotics ActoBitty 2 robot platform (an excellent choice for beginners).
I have also attached the initial basic program. It consists of a collection of subroutines which define the robot control commands. The MKII basic version allows up to 100 subroutines. This approach to basic program design mimics forth, which defines words which are used to define other words. My next steps include motor calibration, addition of avoidance maneuvers, and IR remote control.
Happy New Year!