Got a GPS-GSM tracker today which I ordered some days ago at eBay.
http://www.ebay.com/itm/320762016759

I plan to use the tracker in my biggest FPV plane for location in case of a long range crash.

The housing is a way bulky and heavy even for a big plane. So could not resist to disassemble the tracker to check if size and weight can be reduced.

Here is the outcome:

Some notes about the hardware:

• SiRf Star III GPS chipset, stand alone module, soldered to the main PCB
• GPS antenna is detachable, fixed by two solder blobs
• plug-on GSM module
• GSM antenna seems to be crap, but there is a U.FL socket on the GSM module to connect a better antenna
• 8-pin USB Connector, at least the USB logo is on the charger plug
• Microcontroller STC 89LE58RD
• there is a microphone
• Weight of empty housing: 22.2g
• Weight of PCB including GSM modem: 21.6g
• Weight of battery: 18.3g

[Update]

I have added a picture which show two pads for the microcontrollers serial interface.
Parameters are 19200 Baud 8N1. After power up (without SIM card) there is a loop transmission of AT+CREG.