It sounds like you'd like to have the ability to move the cursor around (or maybe I assumed that!), so in that case, I think that a wireless mouse would be best.
If you are just going through a presentation, then I would recommend something like this:
http://www.tigerdirect.com/applicati...6013&CatId=627
Of course, it looks like they discontinued it. But something similar would do the trick. We have a few of these bad boys kicking around at work. Basic forward, back, laser, blank screen functions. It also has a timer that we never use, but you can have it count down and vibrate at certain intervals to keep you on track.