I have #$%* tons of tattoos. started young. so I can't really talk about what others do to their body.
but as far as piercings, not into it. I don't like having anything hanging off of me that would be detrimental in a fight. if the guy in that last pick pissed me off, I'd just grab him by his stupid easter island ears like a school teacher, right? or what if you had to squeeze through something tight while fleeing for your life from a pack of hungry cujos. you'd get stuck on all yer doo-dads. it's like long hair. way too much of a pain in the ass. I always consider the practical side.
tattoos are cool, cuz they can't remove them when you go to jail. and they don't slow you down.