I've been doing a series of presentations here at the InSTEDD lab in Phom Penh, and so far the best-received one has been (to my surprise) about something I really just getting into: OpenStreetMap. I figured that this would be a good-spirited critical discussion about FOSS philosophy given that Google was in town. :) I wasn't expecting it to be quite so engaging for the lab though — I think they all had a great time.
I am an OSM newbie myself so I was just happy that we managed to get everything working end to end (using GPS devices kindly loaned by the OSM Foundation — thanks Mikel!) Also thanks to Chippy for leading the OSM session last month that answered my questions about the OSM toolchain and gave me the idea for doing an intro party in Phonm Penh. I ripped off most of your presentation, Tim!