Thanks to Jon M. for this submission. If you don't know who Joseph Gordon-Levitt is by name, I'm sure you will recognize some of the stuff he has done. He has been acting since he was a young child, so he has been around quite awhile. I first saw him in the Disney movie Angels in the Outfield back in 1994, but I most remember him as Tommy Solomon on the comedy Third Rock from the Sun. Currently, he is starring alongside Leonardo DiCaprio in Inception.
Unfortunately for Joseph, his hairline is growing up faster than he is. Or maybe growing is the wrong word. Here are some recent pictures of Joseph, where you can see the sidelines receeding: