A blog by Devendra Tewari
Inspired by the article at Techcrunch here are some more tips:
Four fingers drag up (iPad) - brings up the app switcher.
Five finger pinch (iPad) - shows the home screen.
Go to Settings, select General, then select Accessibility; turn Assistive Touch on, and it will add a floating home button to your screen.
In the keyboard, touch and hold a key to bring up special characters associated with that key
Moving icons around and want to exit the squiggly icons mode without using the home button? Pull down the notification center.