If you do presentations for a living, or at least as a regular part of your day job, I like having an option to do something different for presentations now and then. pptPlex from OfficeLabs is kinda cool.
Nathan Dunlap and Robby Ingebretsen did something that looks simiar for a MIX '06 session using WPF/XAML, also fun if you are/were a comic book fan.
While I'm talking presentations, I hope everyone has seen what has been called the Lessig method in this presentation about Identity 2.0. One of Prof. Lawrence Lessig's original presentations is available here.
Lastly, I read the Presentation Zen blog semi-regularly to try to be a better presenter. Hopefully, nobody falls asleep during a presentation I do 😉