Just some extra information for who is reading this thread:
There are boards with gyro, accelerometer, magnetometer, and pressure sensor.
They are used in RC plains and helicopters.
The only thing to add is a GPS module.
This one on Ebay: Mini 9 DOF IMU with BMP085 Pressure Sensor! Use with Arduino Pro Mini! | eBay
You can find more if you google: [9dof baro*] or search for [10dof]
If just found some boards that has also GPS. Search for: [11dof]