I never got one even though I talked about it way back when (20 years ago) - probably more to get a reaction out of my dad. I could never come up with a good location to put it or something that would mean enough to have tattooed into my skin.
Now I'm glad that I didn't! I'm sure that I would have picked something stupid!

Frankly, now it feels like I'm too old to get one. I have been thinking about getting some 'hidden' piercingly though...