AirBeam!

AirBeam allows you to watch and hear on your AppleTV what the cameras of your iPhone, iPod, iPad or Mac sees and hears. AirBeam receives high quality video and audio in realtime from the cameras and microphones of any number of iPhones, iPods, iPads or Mac computers on a Wi-Fi network - even from multiple devices simultaneously. AirBeam for iOS and AirBeam Pro for OSX are separate Apps and are available as a separate purchase via the iTunes or Mac App Store.