Dexter Industries has new product: the DI IMU. An IMU or Inertial Measurement Unit is a sensor that can measure rotation and acceleration about the x, y, and z axis. This sensors has a ton of applications, from data logging different movements, to balancing a segway. In addition to its awesome uses, the sensor is small, so it can be easily integrated into a robot. While much of the software is still in development, you can see some initial readings on the screen (sorry for the bad picture). Just think if you couple this bad boy with NXTBee, you now have a wireless IMU.