How can I force quit an iPhone application?
Sometimes an iPhone app will become unresponsive, and no matter what buttons you press or where you touch on the screen nothing happens. In this event, sometimes it helps to force quit the application.
Apple has made some changes with the iPhone OS 3.0 firmware and the iPhone 3GS release. Those with older iPhones will remember that to force quit an application you could just hold down the home button until the app exited.