Perhaps you are busy.
Staying up to date with all of the useful features Apple squeezes into an iDevice is a full time job.
Here are two we found useful, as well as a link to quite a few more intended to save you time..
Force quitting an application
Occasionally an application will freeze on your iPhone. All you need to do to force quit that app is hold the Home button for 6 seconds.
Volume up button makes a more ergonomic shutter
An iOS 5 addition causes the volume up button to double as a second shutter button from within the camera app.
Is your phone is running noticeably slowly than it used to?