
Years ago, I built a "young Einstein" minifig because I didn't have the sort of white hair or mustache face I thought he needed. With an Ice Planet minifig from BrickFest and a recent order of non-production parts from Germany, I finally had what I needed for an older version of Time Magazine's "Person of the Century."
I amused myself by having young Einstein and old Einstein argue with each other about time travel:

Young Einstein is dressed for work at the Swiss patent office. Old Einstein is dressed not as you'll see him in publicity photos, but as my wife's grandfather always described him: Grandpa was studying at Westminster Choir College when Einstein taught at Princeton in the late 1940s and early 1950s. Einstein apparently wandered the neighborhoods of Princeton, New Jersey wearing a ratty old sweatshirt, hair standing on end, talking to himself.

Click either picture to see more pictures on Flickr, with semi-relevant Einstein quotes for each.