I can't remember if I blogged about this subject. If I already have, sorry for the repeat.
Call me passionless, but there's nothing that I would want etched onto my body forever - or until I am incinerated or my skin decomposes (for the literal, sorry for the macabre). It seems like many people have tattoos with pictures, quotes, names, symbols, etc. Maybe it's only half. Or even less than half. Or maybe that the people with tattoos are likely to wear less clothes.
We should commission a study.
Maybe it's a medium that many people use to show the rest of the world (or significant others, for those more "hidden" tattoos) what is important to them. I choose not to partake in that medium. The pain doesn't deter me. I just don't see the point in getting a tattoo. Whenever I get a stamp on my hand for one reason or the other, I'm ready to scrub it off in a few minutes. I think I'd have a similar disgust for tattoos on myself.
Ultimately, it's a personal decision. If tattoos are the way to display your passions and what's important to you, have at it. My un-tattooed self will sit on the sidelines and watch you get your tattoo.