I’m working on a new game that depends on the accelerometer, which makes testing in the simulator difficult. I asked on Twitter about a hack to use the accelerometer in the simulator and was pointed to iSimulate.
iSimulate is a brilliant application that runs on your iPhone, along with a library that needs to be linked into simulator builds of your application. The iSimulate application connects to your computer over your wireless network and lets you send accelerometer, compass, and multi-touch events to the iSimulate-enabled application running in the simulator.
After you finish developing your app, you can then use iSimulate to record video trailers & demos of your app.