Well, it's a word. It refers to one's body or soul, or both depending on your point of view.... according to the Oxford Little English Dictionary, it's the reflexive, emphatic form of "you"

7/20/10 - None of my photos are edited, except "Clear water in the Reservoir (gasp!)", which was cropped, "Anxious Cat", "Totally Unaffected by Society Cat", and "037", which were rotated, and all photos that say "Edit", in the title.