A new article at Small Times discusses the growing importance of tiny gyroscopes and accelerometers for use as sensors in the next generation of robots. Together these sensors form an Inertial Measurement Unit (IMU) and provide robots with a sense of acceleration and angular rate of rotational motion in multiple degrees of freedom. An IMU is a must if you're building a Segway-like 2 wheel balancing robot, a dynamically balancing biped, an AUV or any number of other advanced robot designs. The cost of building an IMU has been greatly reduced in recent years thanks to high-performance, low-cost MEMS gyros and accelerometers. Companies like Rotomotion are now able to sell complete IMUs inexpensive enough for hobbyists but of high enough quality for commercial and military applications.