Wireless Arduino Programming with Xbee

A while back I started working on a robot that's a completely enclosed sphere. I was inspired, in part, by the commercial robots like this created by Rotundus. Work progressed until I hit a snag - how do I program this thing?! You see, having everything inside the sphere made it a royal pain to reprogram the robot. It slowed testing to a crawl. For a while I just drove it around via RC control. The kids I showed it to loved it, and they all begged for me the finish it. It wasn't until recently that I worked up the momentum (because a PhD, new baby, and launching RobotBox wasn't enough ... ) to start working on it again, but I still had to solve my programming problem.

After much though, it seems that the best way of doing this is by wirelessly reprogramming the microcontroller. It turns out that this is much easier said than done. Sparkfun (and others) sell a nice Xbee Shield for the Arduino Duemilanove, which should work. So, I purchased 2 Xbee's (series 1), a USB Xbee explorer, and a Xbee Shield for my Arduino. Now I'm in the process of getting everything working so that I can wireless program the Arduino via the Xbee in the Explorer USB. It's tough. There's several articles online about doing this, but none specifically address the Xbee Shield, which appears to already have a reset transistor included. I'll report back when I've gotten it figured out!