Haiku Deck is the best application for creating presentations on iPad
Not sure why I hadn't heard of Haiku Deck before, but I've been playing with it for a few days now and quite like it. I was going to say it's a great app for quick and dirty presentation builds, but I've learned it's not so quick (I tend to tinker quite a bit) and it's not that dirty (limited functionality compared to Keynote, but fairly decent results).
I loved putting together this little biographical deck above. It's something I can adapt to kick off a workshop. All but one of the pictures are mine, and I found being able to pull down a Creative Commons image right from within the app itself very handy. Take the time to explore Haiku Deck. You're bound to find a use for it somewhere.