httpv://www.youtube.com/watch?v=SAEH1H-4Siw
Following our handy video roundup of new OS X Mountain Lion features, InsanelyGreatMac has published a video walkthrough of AirPlay, which allows you to mirror your Mac’s display on a television hooked up to the Apple TV.
As you can see, the feature works in much the same way as AirPlay on an iOS device, sending both video and audio from your Mac to your TV over a wireless network.