Longhorn engineer has has a nice and clean robot build with an MSP430 Lauchpad as Brains on his web-page. I like especially the design of the power supply:
It has 3 switching power supplies providing 3V at 4A, 3.3V at 500mA, and 5V at 1A. The main power source is a single cell 3.7V lithium battery. The robot has a on board lithium battery charger and the protection circuit it needs.