http:://www.lambda.org ?

My plan is Lambda on the left shoulder, Pi on the right. Lambda for programming and right-brain, Pi for math and left-brain. I feel that they are simple, elegant, and have a lot of meaning. My only worry is that they won't age well, but I have no knowledge of tattoos.

I made a deal with myself and my wife that I will get both tattoos once I have made a living working for myself (either a successful startup exit or my consulting taking off).

I did this a couple years back -- thus far my only tattoo. It sums up a large portion of my life in one beautiful symbol. http://desmond.yfrog.com/Himg129/scaled.php?tn=0&server=...

Or people will think you like the game Half-life that little bit too much.

I'd go with this one: http://www.conwaylife.com/wiki/index.php?title=Garden_of_Ede...

It is the smallest Garden of Eden, is rotationally symmetric, evolves to nothing, and looks cool.