For me, this is the pinnacle of iPad awesomeness. I feel that this is a very viable alternative to a SMARTBoard or other interactive whiteboard.

Fair warning: This is actually kind of a misleading title -- really this makes your iPad a wireless, touchscreen monitor for your computer.

You will need:
an iPad
a Mac or PC equipped with wireless
an LCD projector (hooked up to your computer)
a presentation/drawing/notetaking app on your computer
a wireless network (you can make your computer a wireless hub if you don't have a router)

The magic is an app called AirDisplay. This app allows your iPad to become a wireless 2nd (TOUCHSCREEN!) monitor for your computer. It consists of two parts. From the iTunes store, purchase ($10) and install AirDisplay on your iPad. Then download and install AirDisplay (for free) onto your Mac or PC. Launch the AirDisplay app on your iPad, and then select your iPad from the AirDisplay menu in the menubar of your Mac. You might need to go into System Preferences and change the arrangement of your displays so that the "Mirror Displays" box is checked. Then your iPad will mirror your Mac, so you will see your Mac screen on your iPad. Launch a drawing/presentation app on your mac, and choose a pen tool. You can then use your finger (or better yet, a stylus) to draw in the iPad and it will appear on your Mac. If your Mac is also hooked up to a projector, the image will appear for all to see. Unlike other screensharing/VNC apps I tried, AirDisplay's connection is fast enough to keep up with your note-taking.

I used to have a SMARTBoard, but I find this far superior. I don't have to turn my back to the class to write on this. In fact, I can stand anywhere in the room and deliver my lesson. Perfect for lurking behind off-task students! I also had a wireless graphics tablet/Airliner. This solution is better because I can see what I'm writing on the iPad. Before, I had to write while looking up at the big screen. I got pretty good at it, but when I handed the tablet to students they would waste a bunch of time because it was so difficult to coordinate. Since you can see what you're writing on the iPad, it's easy enough that I can pass it to students and they can solve problems on the big screen. This is also superior to an interactive whiteboard in that the cheapest iPad (which is more than sufficient to this task) costs $400 (new -- a used or refurbished iPad would be much less expensive!) An interactive whiteboard costs roughly $2000, so 5 teachers could do this for the price of a single IWB.

For my presentation software, I'm currently using the SMARTNotebook software to present my lessons. The nice thing is that, like PowerPoint, I can type parts up ahead of time, but still do problems (I'm a math teacher) on the spot with my classes. Then at the end of class I can export the presentation as a pdf and upload it to my webpage. Unfortunately, PowerPoint for Mac will not save the ink annotations, so whenever you turn the page your handwritten notes get erased. Keynote doesn't seem to even have a pen tool. If you don't have a code for the SMARTNotebook software sitting around in your inbox, you could look at using a graphics/drawing application, or perhaps Notebook from Circus Ponies, which has a pen tool (and is a pretty cool app in it's own right).

A "how to" map for displaying your iPad on a projector via Apple TV and other alternative solutions.
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