AirServer is a Mac/PC application that enables you to stream or mirror your iPad/iPod/iPhone, to your Mac/PC. If your computer is then connected to a secondary or alternative display, such as an interactive whiteboard plus projector, your device will be shown on that display. If your iOS device allows Mirroring then anything you see on that device can be displayed on the big screen.

The AirPlay app is free on a 7 day trial and you can buy a 5 machine licence for $15. You can Download Air Server here

Also check out this post on the iPad Educators Ning group for more information.

As an alternative – also check out Reflection which is now available for PC as well as Mac. Try both for free and see which one works best for you!