The sad thing is there is not an app solution for this. On the iPhone 3G or earlier there was a way to do this but on the iPhone 3gs or iPhone4 there isn’t a one touch way to do it due to Apple’s app restrictions.
Here is the best way I know how:
- Double Click the home button so the screen slides up and shows the ‘running’ apps.
- Hold your finger on one of the apps until they start shaking.
- Each of the apps will have a small red circle with a line. Click the circle to truly kill the app.
Let me know if you have found a better way in the comments!