This is my homemade 10-DOF built up around a 33FJ64MC202 16-bits dsPIC microcontroller. Further more is uses a ITG3200 gyro, BMA180 accelerometer, BMP085 pressure sensor and a HMC5883L 3-axis magnetic sensor. All the filtering is done by the dsPIC. I'm using a kalman filter for the angles and a FIR filter for the altitude. Normally it communicates over a 5MHz SPI interface with data ready and SS. (RS232 for debugging) Tilt compensation for the magnetic sensor works fine now too.
This unit works perfect in my quadrocopter, where i originally designed it for. But you can use it for a lot of other applications as well.
See the 10DOF in action here: https://www.youtube.com/watch?v=DtUdlfKq6_U