If you scroll down to my last update, you'll see I was using the iPad frequently for Greek Archaeology slide show presentations in January. I'm doing this less now: it is nice to be able to annotate the slides occasionally (using Doceri), but since I don't put a lot of annotation on each slide, it becomes cumbersome to wait for Doceri to pop in and out of "drawing mode." Additionally, I had a problem a few weeks back where Doceri suddenly told me that my password was incorrect, which threw me through a loop because I don't remember ever entering a password, and I certainly haven't changed it, but now suddenly it is "incorrect" so I can't use Doceri and I haven't had the time to fix it yet.
I have started using the iPad more often in my smaller class particularly because that room does not have a computer, only a large monitor. I hook the ipad up to the monitor via cable. It doesn't do anything more or less than hooking up a laptop would, but I much prefer the ipad simply because it is smaller and more portable, and because it runs on flash memory, which means that it starts up faster than a laptop (or at least my laptop, which is not a Macbook Air). I use SlideShark in this class, and it works well for my purposes - all I need in this class is a slide advancer and a laser pointer. Also, the "presenter mode" of SlideShark is helpful (you are not able to do presenter mode in Doceri).