One of the least publicized features in iOS 5 is the ability of the iPad 2 (and, apparently, the iPhone 4S) to wirelessly mirror its screen to a second-generation Apple TV. If both your iPad and your Apple TV are fully up-to-date, here's how you activate mirror mode
Don't look for the controls in the Settings app on your iPad. Instead, they are snuggled next to the iPod controls. Double-press your home button to see the multitasking bar, showing all your recent apps. Swipe your finger from right to left; you'll see the Airplay icon. Tap on that, select your Apple TV and toggle the mirror button to 'on'.
