As part of a larger project to create a driving simulation game, Instructables user "searx" has made a fascinating type of game controller. It can sense the controller's position relative to gravitational force, and reports the data back to a PC via Arduino. This can be read by python or other software to act on the controller's position. The controller itself is simple - by attaching weights to two potentiometers - their value will change depending on the way the controller is held, and thus the relationship with the position can be read.
You too can measure various movements and changes in g-force with our AM3X: accelerometer module. This tiny 3-axis accelerometer module can operate in either +/-1.5g or +/-6g ranges, giving your project the ability to tell which way is up. Ideal for robotics projects, tilt sensors, vehicle dataloggers, and whatever else you can dream up. It even has a "zero g!" output to detect when the device is in free-fall, so you could connect that to an "interrupt" pin on an Arduino to have your project react immediately if it's dropped! For more information and to order, visit the product page.