I've been wanting to do this for a long time now. Finally worked up the nerve to make it happen! I chose the seven brightest stars in the M45 star cluster, better known as the Pleiades. That's five of the "seven sisters" from Greek Mythology plus their parents. (From an apparent magnitude standpoint, the other two sisters were a little too puny to include.) My star, 20 Tauri, is at the top right of the central "box." ∞
Update: My tattoo is now featured in the astronomy section of Science Ink, a marvelous collection of math and science tattoos from noted science writer Carl Zimmer!