the link below seems to be a pretty good one, there are other sites as well, but this was the fist one that i looked at. i will also post it in the public forums.

http://tattoos.lovetoknow.com/Prison_Tattoos

Whazzup? Can't sleep, so I thought I would do a little surfing! Thought I would do a little research on prison tattoos...what they mean and all. Any ideas on where I could find them on the web? This site maybe? See ya in the lobby!