Please pardon my absence - iPads happened. (I'm hoping for sympathetic nods here.)
Speaking of iPads, let's talk about a program called Reflector. It is my new best friend. Reflector is a one-time-fee download that allows you to display your iPad through your computer (and assumed data projector) untethered. The program costs $12.99, and there is a break in price is you buy in bundles of five. I used the program last week with two teacher trainings, and it worked flawlessly. I even embarrassed myself a bit when I played a video on my iPad and the sound started blasting from the speakers on my SMART board. (I didn't know Reflector could do that!)
It is sort of a little process to get the file downloaded and enter your registration key, so I've included instructions on the setup. Once the program has been installed, you really never have to even open it again. It waits on you in your system tray for you to double-tap your home button, swipe right, and start displaying. You can even have multiple iPads display at once, though it is hard to see details after about three. If you need help using Reflector after it's downloaded, check out this use quick-guide.