The LEGO mindstorm robotics kit is a popular programmable controller that can allow kids and adults alike to enter the world of robotics. I am currently playing with a few free software programs that my friend found that let you simulate virtual robots, including the mindstorm.
LEGO Digital Designer – Just for fun, build something!
Microsoft Robotics Developer Studio – This allows you to model a virtual robot and world, complete with controls to maneuver your robo-friend.
Modeling Programs we are investigating to see if they can be used to construct virtual robots or the worlds they live in: Wings3d, Silo3d, Blender3d
Mindstorm blog:
http://thenxtstep.blogspot.com/