I'm really excited to announce that Kyle (KJ6KUV), a great contributor to this project, is launching a balloon and he'll be using a Trackuino board to track its payload. He'll be launching from the Oxnard airport (California) on sunday april 17 around 8:00 am pacific time.
To track the balloon online go to this page. It will have the most recent position as well as the previous positions reported: http://aprs.fi/?call=KJ6KUV-11
Best of luck with the chase!