The human brain is not linear and I struggle quite often to get my ideas in a presentation. I like to use mind mapping techniques to sort ideas and create stories. Most presentation solutions today unfortunately are based on slides placed in a fixed sequence resulting in a lot of duplication with 'summary' slides. Cool animations and transformations try to cover up the non linear patterns of my brain.
While checking out some web based online presentation tools I found Prezi - The zooming presentation editor. This is something really different and extremely cool. Just to give you an idea check out the embedded presentation I quickly created based on some earlier created material. If it doesn't show you can also find it here.