Measure velocity, acceleration, and heading with one integrated circuit: Sparkfun’s 9 Degrees of Freedom IMU Breakout.
The product has a 3-axis accelerometer, 3-axis gyroscope, and 3-axis magnetometer. That’s right: nine degrees of freedom in IC! Each sensor has a wide range, too. The accelerometer’s scale can be set to ± 2, 4, 8, or 16 g, the gyroscope supports ± 245, 500, and 2000 °/s, and the magnetometer has full-scale ranges of ± 2, 4, 12, or 16 gauss.
Incorporate this breakout board into your next product and you’ll get data on acceleration in x/y/z, angular rotation in x/y/z, and magnetic force in x/y/z. It works with lots of microcontrollers because it supports both I2C and SPI.
You can buy this board for $24.95 from Sparkfun.