iOS has a lot of small shortcuts that people may not know about, making it quicker to do certain things:
Tapping the status bar:
You can scroll all the way to the top of a long list or table very quickly by simply tapping the status bar at the top of your phone (the bar with the time, battery status etc etc)
Tapping a tab bar’s tab:
Most applications have a hierarchy that will get piled up and piled up when you go from section to section. You may find yourself tapping the ‘back’ button dozens of times to get all the way back to the beginning. If the application has a tab bar, just tap that tab and you will go all the way back to the first page.
Zooming in Safari:
Instead of pinching to zoom into an image or block of text in Safari, double tap it and the screen will automatically adjust it to take up as much of the block as possible. Double tap again to get back.
More keyboard characters:
Hold down on a keyboard character to see variations of that character.
Controlling music from lockscreen:
If you double tap the home button on the lock screen you can control your music. This also works for YouTube, you can open a video, lock the phone and then play it from the lockscreen to just listen to the audio while the screen is off.
Take photos with the volume button:
Instead of using the on screen photo button (and nudging the phone enough to mess up your shot), use the volume up button (positioned just like a standard camera’s button).
If you mess something up big time, give your phone a shake to undo.
Panning to photos:
In the camera app you can tap in the bottom left to get to your photos. As of iOS5 you can now just pan across to your photos, and vice versa.
Slower scrubbing in a video:
When watching a video scrubbing can be difficult if you want to get to a precise location in a long video. If you hold the time knob and move your finger down you can adjust how far moving your finger horizontally will affect how far you move in the video.