Byon Garrabrant N6BG is the creator of the TinyTrak3 and other APRS related devices. They are available from www.byonics.com. Also available is the TinyTrak3Plus which has a larger voltage regulator onboard to power a GPS receiver. The tinyTrak SMT uses surface mount components and is much smaller. Unfortunately, the PocketTracker is no longer available because some components are no longer available.
The TinyTrak3 is "transmit only" device. It is capable of SmartBeaconing and can send compressed beacons in Mic-E format.