Help Wanted Again

I have another talk, this one without powerpoint and with a strict 3-4 minute time limit and with the requirement I do research/cite sources. So something a little less light-hearted and more social education-y, I think. Or at least something serious I can get animated about. Any way, I need a topic asap for the talk on Monday and I'm stuck. Those who know me and what I'm into, any suggestions?