GY-521 MPU-6050 Gyroscope Module for Arduino
GY-521 MPU-6050 sensor contains a MEMS accelerometer and a MEMS gyro in a single chip. It is very accurate, since it contains 16-bits analog to digital conversion hardware for each channel. Therefor it captures the x, y, and z channel at the same time. The MPU-6050 is not expensive, since it combines both an accelerometer and a gyro.
Dimensions: 0.79 in x 0.59 in x 0.12 in (2.0 cm x 1.5 cm x 0.3 cm)