When done right, body painting can be an amazing work of art on its own, or as part of a larger image. I've seen everything from superhero costumes, to clothes that, until you really inspect closely, can't tell if they were real or not. In the hands of a true artist, it can be a beautiful, beautiful thing.
This is where my rant starts - the not so artful. When body painting goes wrong in every way possible. Oh I know there is the whole sub-level of drunken spring break “oh look, watermelon painted breasts” is funny. Or it seems funny when you are a drunk reveler I suppose, but then there are attempts to be cute or witty that just fail.