In short talks, the first minute is critical.
Watch how Jane McGonigal handles the first 55 seconds of her seven-minute talk at TED on "Massively MulitPlayer ThumbWrestling." She gets the audience intrigued -- and gives them a roadmap for the remaining six minutes -- in one fell swoop.
Her conclusion isn't as strong (other than having taught you how to play a game, you're left with a bit of a "now what?" question in your head), but the intro is textbook.
What do you think? What do you see?