At yesterday's cohort meeting, we discussed ways that remote whiteboards like AirSketch could be used to demonstrate concepts while the instructor roams the room. One of the most useful tools on the iPad to use in conjunction with a remote whiteboard is the screenshot function.
At any time and in any app, you can take a screenshot or a picture of your iPad's screen by pressing the power and home button at the same time. This takes an image of your screen and saves it to your photo roll. If you find an image on the web, a graphic in an app, or some text you'd like to capture and annotate, this is an easy way to get it quickly.
Here is a short video I made on how to do this: