I've taken to giving presentations that consist solely of browsing and editing content on wiki.
More recently I've found that a single pages with some notes and a lot of references works well for this purpose.
Elemental Talk -- Aug 31, 2012
Notice: I often show content that is only available on my laptop wiki server, localhost:1111. These addresses leak out and appear frequently in these talks. I'll try to edit these references when suitable substitutes become available.
In my earlier attempts I felt the need to prepare more which makes the talks harder to move.