I've got one on my back. Got it in grad school during my pagan phase (well, not that there isn't still a pagan hippie inside me, but these days candles are more often for nice-smelling rooms than anything else

) It's a snake eating its tail with some runes. Not big - maybe the size of a silver dollar. I don't regret getting it, but sometimes I wish I'd gotten it in a place that I could see it without looking in a mirror. It's just above my bra strap. I wanted it in a centered, balanced position on my body but did NOT want a tramp stamp, and didn't want it on my stomach or chest, so on the back it went. It hurt for sure, but not as badly as I thought it would hurt, and there were a few sections that I honestly barely felt at all.
What I would love to do but just haven't gotten around to it yet is to modify it and turn it into a compass rose. And instead of putting the fleur de lis that usually marks North on a compass on the back, I'd put it on the inside of my left wrist - just small so my watch could hide it if I really needed to hide it, but that I could see it and be reminded of what's on my back. The hold up is saving money and finding a place that I trust will do a good job. Buzz really doesn't like the idea of tattoos at all, and I'm sure he'd rather me just leave it alone, but he also knows that if I need to do it for myself, then I'm going to do it. I feel a little bad doing something I know he doesn't like, but ultimately, I have to do this for myself. I believe in talismans and symbols and ritual, and for me, tattoos are a way to carry those talismans with me at all times to help keep me centered and grounded.