I know loads of people that work in Formula 1, and Mark Webber once fell off a bike.
Emma Pooley (Olympic silver medalist) has been known to visit the shop I work at (never buys anything as she's sponsored to high heaven).
My girlfriend's flatmate is James Dobbin, 2006 National hillclimb champion.
I once owned a BMX owned by legendary flatland rider Phil Dolan (who was given it by his then sponsor Fly, sold it to almost-as-legendary flatlander Effraim Catlow when he started his own company, who then sold it to me. I then sold it to some random ebayer).
My sister-in-law's family live in the next town over from where Jeff Jones makes overpriced titanium stuff (I went over there for the wedding, I didn't know he was there at the time or I would have gone had a look for something to pinch).
I have tenuous links to lots of other famous people, Bill Gates, Bono, Robert Duvall, the guy who played Father Jack, Franz Ferdinand, anyone who was in the original Italian Job, England defender Matthew Upson (that's football BTW), Bill Pullman, Bob Geldof, and Matt Groening, to name but a few.