This new feature introduced with iOS6 is sure to find some use among educators and parents who would like to lock the iPad into one app mode, so that the desired app cannot be closed.
To use it, go to Settings/General/Accessibility/Guided Access. Slide the Guided Access switch to turn the feature on, then set a password.
Next, go to the app you want to lock into, triple tap the home button, accept the defaults and touch START.
The iPad will now be locked into the app you have selected.
To leave Guided Access, triple tap the home button, enter the password and touch END.
With this feature active, the home button is inoperative and 4 finger swipes will not reveal the multitask bar or move to other running apps.
Inputting an incorrect password results in a 10 second pause before being allowed to try again.