I just wanted to take the opportunity to let you know about a project I've been working on for the past few months. Mirobot is an open source Turtle robot (based on the Arduino of course!) that's designed to help kids learn about technology and programming. All the files are online so you can make it yourself although I'm probably also going to put it on Kickstarter if anyone's interested.
More details at http://mirobot.io
I built it to play around with my kids, but if anyone's interested in building one themselves (or for their own kids) then let me know if you need any guidance.