Star Tattoos or Star Tatoos?

I've never been much of a grammarian to tell you the truth... that's why I still don't know whether it's spelled "tatoos" or "tatoos" or even "tattooes"!

What does it mean anyway? Too lazy to check out the Wikipedia :-) All I know is I love them star taoos. They look great on the lower back of girls. My girl friend has several.