Yes, but I admit it might have only been because they were all major geeks. We were playing D&D back then and our DM introduced an artifact called The Prime Sword(or something like that). It was the conceptual foundation of all swords, basically. The pattern on which they are all based. One unique aspect of it was that it's fate was tied with that of all other swords. If it gets lost, many swords around the world will get lost. If someone goes to war with it, nations will suddenly beign going to war all over the place.
Our party's cleric liked the idea. She said if we put our hands on it, we should destroy it.
"What do you think would happen then?", she said with a smirkish mile.
"People will invent the gun", I answered,
and everybody went silent for some five minuets.
Also, in biology class a few weeks ago we talked about blood clotting. A chemical called Thrombin is involved.
Being the ADHD freak I am, I was drawing in my notebook and everybody assumed I was just not listening. Then I raised my head and said in a thoughtful tone "Can I cause someone a stroke by injecting him with the stuff, causing his blood to clot within his veins?"
I should have took pictures of everybody's faces then. They were freaking stunned.