I recently purchased a FujiFilm instant camera, the Instax Mini. This was a pure impulse buy after I saw one being used by a photographer friend. This camera and instant film is still sold in stores like WalMart. The film size one the Mini is business card size. It's a classic party camera.
Whip one of these out and everyone wants to get into the action. Something about a physical output and watching the film "develop" is just right.
The camera is dummy proof. Simply pull the lens out to turn the camera on, wait for the light to turn green, select the scene mode, push the button. Out pops the film.
Like I said, it's got party or social gathering written all over it. I even used it last night during a model shoot.