University of Maine High Altitude Balloon Tracking

Iridium
Iridium unit 1
Iridium unit 2
Iridium unit 3
MSU's Site

Amateur Radio APRS
N1YIP-11
AA1PJ-11
W1YA-11

SPOT Trackers   (Note: altitude reading is off at higher altitudes)
SPOT tracker 1
SPOT tracker 2

Fox Hunting Beacons
CW on 433.6 (or possibly 433.4 or 433.2)