Nice post from the latest Hackaton in Malmo Hackerspace:
For the Hackathon event last weekend, we wanted to build a robot and decided to go for a kiwi-drive. The kiwi-drive is a three wheel drive configurations that use special wheels to achieve omnidirectional movement. The robot was designed in Corel Draw (that’s what the laser cutter prefers) during the two weeks leading up to Hackathon and parts were purchased so that everything would be ready when the build started. We also moved the design from Corel Draw, via AutoCAD for cleanup, to SketchUp for a virtual test assembly and rendering to make sure everything would fit together.
[...] The Arduino provides a simple serial interface and does all of the required drive calculations. It also provides an add-on interface that can be accessed using the same serial link and allows up to over a hundred expansions to easily be added to the system. The first two addons will be a battery voltage monitor and an emoticon display.
Want to build one? check the wiki of the ongoing project with part list and code (soon).