I just love some of the examples Carl Zimmer has collected of scientists and their tattoos.
It makes your ying-yang or celtic band seem somewhat, well, crap.
Could you have journalism tattoos? Your name in shorthand, a notebook, a font name and point size, picture of C P Scott, your foot on a doorstep.
What about politics? The Labour rose, Lib Dem pigeon or Cameron's tree I suppose. Sheet music for the Red Flag perhaps, a quote from Burke or Mandela's prison number.
Tough to get it right without it looking a little bit stupid.
And what happens if you cross the floor? You'd be like a friend-of-a-friend-of-a-friend who added the words: "Is a slapper" to his girlfriend's name when their relationship broke down. Another friend-of-a-friend-of-a-friend was a skinhead nicknamed 10 because he tattooed the word Oi (as in the skinhead music) on to his foreheard himself using a mirror. Unfortunately he forgot to account for the reversing effect.
I came across Carl Zimmer's science tattoo collection when it was mentioned in a Utne email newsletter. They ferret out some good stuff.