Accelerometer+Magnetometer Triple-axis (Compass) Board LSM303
This module is the integration of 2 sensors, a 3-axis accelerometer that helps you get the change of velocity of an object, sensing vibrations, and checking orientation, and a magnetometer to locate where true NORTH is.
It uses I2C, so integration would be easy with using just 2 pins. Its operating voltage is from 3.3V to 5V. There's also a Data Ready and 2 interrupt pins available. The data ready pin is a pin that indicates when the data is available to be read.
You could use this sensor for projects that need displacement and orientation of an object.