This is Sarah Shay's tattoo:
Yep. It's a semicolon. I'm a grammar and punctuation nerd by nature, and I love the semicolon in particular because, as many semicolon-haters will eagerly point out, you don't "need" them. Unlike the more utilitarian period or comma, a semicolon never really needs to be used. It's a stylistic choice; you can create really elegant sentences with them if you know what you are doing. I'm considering an interrobang on the other wrist.