I have several tattoos of birds and flowers, but not necessarily science ones. I have seen some very cool science tattos, though - including equations (pick a scientific equation that is particularly meaningful) and constellations. Feynman diagrams are popular as tattoos as well. But, as always, an important part of choosing a tattoo is to pick something meaningful to you, and something you can see *staying* meaningful to you for decades!

I have a tattoo but it's of an ancient Irish word for home (as an immigrant, keeping connected to my roots is important to me). But I have a friend who has an awesome tattoo of the telescope she works for (Gemini South) and the night sky she sees down there. Its very cool. I have another friend who is a HUGE star trek fan and she has tributes to star trek as a tattoo sleeve.