I think the solution lies within this video:
http://www.youtube.com/watch?v=qp0HIF3SfI4No need to watch the whole thing and, for those who've viewed it before, re-view it again starting at 2:00, or skip to 4:05 where I feel the answer lies.
I really liked that video. Here is my try.
"My finances aren't anyone's business but my own. Bitcoin means I don't disclose or ask for anyone's permission when I make a transaction. Bitcoin lets me safely store, send, and receive money with anyone in the world for less than a penny per transaction. Unlike using my bank, credit card, or PayPal, I am the only one who controls my money, and there is no middleman taking a cut."
This is shorter that 30s, I might add, "It uses the same top-of-the-line encryption technology as the US government, so my money is more secure than if I stored in Fort Knox."
Might be a little weird to do it cold, but if you want to get bold you could try to buy coins from random people. Just be like "I need some bitcoins, do you know anyone?". You'll get like 100% nos of course, but you'll up exposure and it's just odd enough an interaction you'll probably get a solid % googling it later. And it'll help them understand right away that bitcoin isn't a MtGox(tm) product, you can buy it from your peers on the street.
Cool idea.
"Like Western Union via email and almost no fees."
Short and sweet.