I recently had a conversation with someone who was enthusiastic about nanotech in the abstract, and had studied computer science, but hadn't thought a lot about the implications of advanced nanotech manufacturing. The idea that it might have a downside was new to him.
I started him out slowly, with the idea of intrusive advertising. "You know those planes you see above Miami Beach, towing banners? OK, now imagine a very small plane towing a banner a few inches high--right in front of your face." I indicated the size, waving my hands just inside his personal space for added impact.
"Now imagine a smaller thing like a bug, that lands in your ear and gives you a thirty-second Coke commercial." After thinking about the two-inch airplane, he found this easy to grasp--and he didn't like it at all.
This was enough to get him thinking about surveillance. Within the next twenty minutes, we were able to cover the possibility of weapons and the possibility of unstable arms races, the likelihood of government control, and the need for--and lack of--a legitimate global police organization. It wasn't just me preaching--he was volunteering comments like "The CIA will be all over this." There was no doubt he was engaged and thinking creatively.
I'd like to get suggestions from the audience: when you introduce new people to advanced nanotech, how do you give them a sense of its implications?