I heard about a new graphical environment for Arduino boards, called ModKit, ready to emerge from alpha testing. Want to teach your kids (or a club) to program their Arduino robots? This is the best tool for the task. Easy to use blocs stack together much like the old Lego Mindstorms GUI, making programming fun to explore. Then you can see the generated Arduino code, modify it if needed and upload it directly from the browser. Oh, did I mention you can use it online?