A couple of months back I wrote a book review for Presentation Zen - Simples Ideas On Presentation Design And Delivery by Garr Reynolds and posted it here: Get Yourself To Presentation Zen. It is, without a doubt, one of the best books on presenting, presentation skills, and how to use software like PowerPoint with much efficacy and effect. Garr might even be more widely known for his fascinating Blog on the same topic, Presentation Zen.
During a recent trip to the West Coast (Garr is based in Japan), he stopped by Google HQ (aka the Googleplex) and gave a presentation. In case you did not know, these Google presentations are frequently posted over here: Talks@Google. If you love Ted Talks, you'll love Talks@Google.