Epson lays claim to the world's smallest high-performance inertial measurement unit (IMU) -- the V340 is a six-axis high-precision gyroscope/accelerometer combo that measures just 12x10x4 millimeters.
I just wished the maximum rotation speed was quite a bit faster. 450 degrees a second may sound like a not, but even for personal navigation that could be too slow. It will depend on whether thats instantaneous of average. A person walking and turning around can do 180 degrees in less than 1/2 a second and peaks much higher. Same even for a car doing a U-Turn.