$20 6-DOF IMU with atmega

[Razor Concepts]

Just a heads up - if you want a cheap IMU, check out the Witespy flip for $20
http://witespyquad.gostorego.com/flight-controllers/flip-mwc-flight-controller.html

It's designed for quadrotors but it has all the parts you need for a good little IMU. It has the 6050 3-axis accelerometer and 3-axis gyro, an onboard atmega and a USB port. All for $20!