Many articles and web sites have taken note recently of the proliferation of literary tattoos, and the blogs that love them.
(Here's one of my personal faves:)
Now, I've discovered another group of intellectuals who like to wear their academic discipline as a sleeve (or at least on the small of their back, or on their bicep) -- scientists. At Carl Zimmer's Science Tattoo Emporium, science journalist and author Zimmer (whose most recent tome, an homage to E. coli bacteria, is sitting on my bedside table) collects images of beinked flesh with scientific themes such as molecular structures, species of fish, or chemical symbols.
Some are more subtle...