I find this thread very interesting. I've liked tattoos all my life. As a kid and through my teen years I always have been drawing on myself in school. My mom would constantly facepalm over her retarded son every time he had drawn a watch on his wrist or covered his arm in characters, descriptions and his own religion made up entirely of arobic dinosaurs.
However, I've always been at odds with it, as I've never found anything worthy. Yin and Yang symbol is the only thing. It's the only fundamental truth that I believe in, and it's not because I'm involved with Asian culture or understand Taoism. I just love the simplicity and feel of the Ying and Yang. It's a philosophy that means the world to me. However, getting a Ying/Yang is so general. It's like getting a handicapped restroom sign on my back. It's great and all, but it's not special enough to cover up your own body.
I think what I have found out during this thread is that I need to develop myself and my jiu-jitsu skills, and find something in my style, thoughts or process that defines me, and then apply it in a jiu jitsu way. Maybe If I become skilled at a weird guard, I might be able to apply it or express it in some ying and yang-like symbolic way.