I've had a few reverse situations where people thought I was a celebrity.
One girl in college insisted I was John Cafferty (from J.C. and the Beaver Brown Band). Although I kept insisting I wasn't, it didn't help that the guy next to me thought it was funny and kept saying "tell her the truth man".
I used to walk by the St. Louis Cardinals stadium every day on the way out of work while players were arriving, and someone thought I was Joe Magraine (old pitcher for the Cards) and asked for an autograph.
Semi related (although I'm getting way off topic now), my first trip to Jamaica, the hotel manager said he managed a hotel in downtown St. Louis when they won the World Series in the early 80's. He had a striking resemblance to shortstop Ozzie Smith, and he frequently wore a Cardinals jacket. He said after a while, it was much easier just signing autographs than trying to convince people he wasn't Ozzie Smith (you'd think the accent would give it away!). Said there's a whole lot of fake Ozzie Smith autographs floating around St. Louis!