TinyTrak
From APRSWiki
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 a "transmit only" device. It is capable of SmartBeaconing and CornerPegging, plus it can send compressed beacons in Mic-E format.