I use it for my photography clients to walk through images via Lightroom. They watch the big screen HDTV and see large images while I can look through my Grid or Develop view on my laptop.
Here's a diagram I created to show how it works (photos are real but simulated on the devices).
All you need is a computer, an iPad (1 or 2), an HDTV with HDMI input, Air Display and an Apple iPad HDMI adapter.
- Download Air Display
- Install Air Display on your Mac and iPad
- Turn Air Display on for your Mac and select your iPad
- Turn off "mirror display" in your System Preferences>Display Settings (personally, I prefer having my Grid displayed on my Macbook and only the image on my iPad/HDTV but you can mirror your display also)
- Connect your iPad to your HDTV via the Apple iPad HDMI adapter
- Display anything you want now!