Bravo to David Maister for his advocacy of using an overhead projector versus PowerPoint!
I've found the same thing: the overhead projector produces a closer connnection with the audience. You're writing lists as you move along and the presentation is less rigid. That's why for some topics, I refuse to use PowerPoint.
One of David's commenters suggests TabletPC as a more high-tech alternative. I'd be interested in hearing from anyone who's used that product.