I found this website - http://www.cooking-hacks.com/blog/tutor ... eluxe-pack - on how to build a GPS tracking device. Its in the UK. I ordered everything that it lists to use ( except I bought the 900MHz Xbee module as not to interfere with the 2.4GHz DJI controller ) from this website in the USA - http://microcontrollershop.com/default.php - it will be delivered next week and I'll put it all together and mount it on my F550 FlameWheel. Right now I'm not sure what the weight will be, but the Arduino Uno weighs about 28 grams so I'm figuring that it will weigh around 75 grams total possibly less. Total cost plus shipping is about $285.00. Here's the list of what I purchased. 2 x Arduino XBee Shield Add-On Board $49.90 2 x Arduino Uno R3, ATmega328 USB Board $49.80 1 x GPS Module for Arduino $65.00 1 x Internal GPS Antenna, U.FL Connector $10.80 2 x XBee-PRO DigiMesh 900HP S3B Module, 250 mW, Wire Antenna $86.00 Hopefully it works. I'll let you know when I get it setup.