Arduino in the Elementary Classroom

I have recently started to use Arduino micro controller boards to provide an opportunity for fifth and sixth graders to experiment with building and controlling circuits. Students write code, verify, and upload the program to the Arduino board using Sketch an integrated development environment. You can build simple circuits like a blinking light and create programmable robots. Is there anyone else in this community doing the same thing or something similar? What technology do you use? How are you implementing this in the classroom?