It is VERY attractive. I really like back tattoos (not tramp stamps, but full back pieces) on girls, laying in bed with a girl tracing her tattoos with my fingers. I just love tattoos in general. Except on the face, that's going a bit far.
As much as I've tried I just can't get into a girl with a tattoo. I agree it's a double standard among many men, but I just don't find it very lady like. I suppose it depends on the man, but personally I prefer women that are more traditional. I like elegance and class. I don't by any means infer that girls, or anyone, that have them aren't classy. I just think it's one of those instances that you can't go wrong by not having one.