My first slide was a picture of the Diebold AccuVote machine. The moment it went up on the big screen, before i said a word explaining what it was, the room was filled with boos. I guess my audience was already familiar with some of the problems of electronic voting. :)
The talk was pretty well received. The slide revealing the size of my Python prototype (currently under 400 lines, as compared to Diebold's code at over 31000 lines) even drew a few cheers.
A few people have come up to me to say that they liked the talk, so i think it went well.