The iPod Photo and Keynote 2
The Apple presentation software Keynote 2 allows you to export your presentations as images, among other formats. I really like that they added support for exporting to Flash.
Someone on macosxhints posted that you can use this export feature to create an image for each slide, then load those images into your iPod Photo. Connect the iPod photo to a projector or TV, and you have a truly mobile presentation system.
Now if only there was a remote that would allow you to control the pictures. Apparently the included remote doesn’t, and neither does the NaviPod.