I wonder what people would think of trying to get the radar module from the hotwheels radar guns, seen at http://www.amazon.com/Mattel-J2358-Hot- … B000EHLB0M, or similar to play with. Could think of some cool stuff to do with them…
What do we think?
http://www.youtube.com/watch?v=Dhp21FxttWM… 
Should get people started.
Look for info on the X-Band Motion Detector by parallax, that should help. Or you could just buy that module also.
http://www.satistronics.com/Wholesale-s … ules_c1175 Oooh! Cheap! 