Pavel  has some great posts on his blog about robotic vehicles using the .NET Micro Framework .
"When I was invited to TechEd North America 2008, I didn't want to go with "bare hands". That's how the simple robotic vehicle was build, completely based on .NET Micro Framework . Module in the vehicle is the smallest .NET Micro Framework module on the market, the Digi Connect ME . Remote controller is based on Tahoe development board  equipped with accelerometer. For communication are used ZigBee modules from Digi called XBee ."
Read more about the robotic vehicle: