Mark, N4CMB reports in a blog comment that members of the North Texas Balloon Project are launching flight 15 on Saturday, September 1, 2007 at about 13:30 UTC (8:30 am CDT) from the Hillsboro Municipal Airport (32.0835N 97.0971W). The balloon's APRS tracker callsign is W5SJZ-11. It will carry beacons and a crossband FM repeater. Thanks for the note, Mark!
Ilmari-2007b will fly on Sunday, September 2, 2007 at about 06:00 UTC (09:00 EET+DST) from Sappee, KP21GJ. It's APRS tracker callsign is OH2SIX-11. In addition to the beacons Ilmari carries a crossband linear transponder (much like a satellite: it receives on 144 MHz and transmits on 437 MHz) and an 1282 MHz FM-ATV video transmitter.
Update (Monday 3rd of September): Ilmari 2007b was postponed due to bad weather, but NTBP flight 15 did fly on saturday.
Happy tracking, everyone!