Did you know that you can send all system audio from Mountain Lion to an AirPlay device? We’re not talking about the AirPlay mirroring functionality that requires a 2011 Mac. If you’re a fan of Rdio or Spotify (or any other audio based application or game), you can send the audio to an Apple TV even if the application doesn’t have AirPlay built into the program.
Option+Click on the volume icon in your menu bar. Then select Apple TV from the output listing. Boom. Audio is now sent to your Apple TV.
Oh Mountain Lion, you’re so awesome sometimes.