Äh ...

The thought of it feels slightly provocative; a penis must be hidden until it's really needed - for natural needs and reproduction. You don't take it out at dinner parties or during coffee breaks. (...) With this simple handbook we want to show you a natural way to hang out with your own or other dicks. Penisses should be fun, not just functional!

Dick Tricks - The Art Of Genital Origami (slightly NSFW)