Digital Slideshows Made Easy: Projecting Slideshows
Get out the screen and turn down the lights—now the classic slideshow can be updated with modern digital projectors
GretagMacBeth has a great product for serious slideshow presenters, the EyeOne Beamer. This little unit sits on top of your projector and actually lets you calibrate it. The Beamer does a very good job, but results vary, depending on the computer or laptop used and what level of projector you're using (low-end projectors don't calibrate as well, but they do work).