How to End Task or Force Quit an iPhone Application
These are instructions on how to end task or force quit an iPhone application on iPhone OS 3.0.
You may need to do this if an application has stopped responding or is experience other issues.
Make sure the application that you would like to force quit is open.
Press and hold the Power button until the power slider appears.
Press and hold the Home button until the application is forcefully closed.
You may now relaunch the application if so desired.