how to iphone quitting applications to save battery

If you have multiple apps open like Safari, iPod, Youtube, stocks etc., the iPhone may feel "warmer" as you are running all the apps in the background - when you press Home it does NOT actually clear or close apps., and this may affect battery usage.

To actually close (or Quit) an application, HOLD the Home button for about 4-8 seconds while in the application. Apparently this will save battery usage and will also keep it cooler.

(this very helpful tip was shamelessly stolen by me from user 'djmx', original post can be found here)