Replying to What should I do in Denver for 6 hours?

I'm going to visit a buddy who lives in CO after new years and I'm flying into Denver at 9am. He's coming from home as well but lands at 3:30, so he won't be able to drive me up to Vail until later in the day. I don't really want to sit in the airport for 6 hours and try to decipher hidden Nazi conspiracy theories, so does anybody have some suggestions for things to do?

I'm up for doing anything that will leave me in the vicinity of the airport/on the way to Vail by 4 or 4:30, and my only limitation is that I won't have a car and I'll be lugging around a ski bag.