I regularly use my iPad to give presentations using an AppleTV and Airport Express (wireless router).  This works very well as long as your projector or TV has an HDMI interface.  The iPad screen is mirrored via the AppleTV and I have found that this lets me show presentation files (Keynote, PDF), apps, pictures and web pages.  The advantages include audience members being able to take over and show "stuff" that they have on their iPads, me being mobile while presenting and using pan/zoom to control what the audience is focusing on at any moment (combined with being a more modern means of presenting).  The one drawback so far has been having an HDMI capable display device or having to use a VGA docking port adapter and be directly connected.   Kanex recently started selling the ATV Pro, an HDMI input to VGA output converter to address this problem.  I ordered one last week and was able to test it today for the first time.  The first projector that I tried it on produced a reddish tinted display so I tried it on another which worked correctly.  I do not know yet what caused the first one to work poorly but I had no complaints with the second one.  I have a little travel kit containing my setup (AppleTV, Airport Express, power strip, HDMI cable, VGA docking port adapter) which I am now adding the Kanex to.  I will follow up this post with future tests when I have more info.  You can see the ATV Pro at Kanex ATV Pro.