"And he asked a question. And I was like, I’m sorry did you say you were Tom Furness? And he said yes. I said, then I would love to answer your question, but first, will you have lunch with me tomorrow? And there’s a lot in that little moment. There’s a lot of humility, but also asking a person where he can’t possibly say no."
Although, admittedly, that's after you got them to say a few words to you and you're in front of a large group of people.
[1] http://www.youtube.com/watch?v=ji5_MqicxSo 19:40
Edit:
For those who don't know, here's the setting of this talk:
This talk is one in a series given at CMU called the "Last Lecture" series with the hypothetical setting of 'what if you had one last talk to give?'. Randy Pausch, a professor at CMU, didn't have to pretend. He was diagnosed with pancreatic cancer, and in August of 2007 (when he gave the talk) was told he had three to six months left to live.
If you haven't seen it, watch the whole talk. It's really good.