I met Dean because my friend speed-walked through the pits, pulled my arm, and yelled "DEAN KAMEN'S HERE!" in my face while (safely) dragging me out of the pits so that we could get a picture with him. He signed my safety captain button
...after he gave us an elevator speech about the alumni tracking site.
I met FiM president François Castaing because he came by my pit. He found our minibot very cool, and our minibot team had the time of their lives explaining exactly how it worked. He and a VIP spent a while in/by our pit, and "busy" is not a word that I would use to describe their schedule.
I met Dave Lavery because I turned around after a match at IRI and he was talking to my roommate. Talk about unexpected.
I'm going to stop there, since at this point it turns into personal icons, and there aren't really any exciting stories there. I wish I could have met Woodie or any of the celebrities (wil.i.am, Morgan Freeman) in St. Louis this year, but it just didn't happen.