I give many seminars every year, and I use a Kensington laser pointer/presenter that is a few years old and has more than a few miles on it. It is very simple, no bells and whistles (no mouse). I tend to walk around the room as I talk, and I've never been out of range with it.

If you only need to click through slides and use a laser pointer, I'd recommend going for a simple device. I learned from using various devices at conferences that some of them are confusing and you end up doing unintentional things with your presentation (at least I do, I'm a KISS person!).

drsusan