Patience is a Virtue. As photographers who appreciate the traditional methods of photography, patience is essential. We don't often know what the end products of our photographs will be before processing and scanning. This is something that we have come to accept, and for the most part, even embrace. But sometimes, you just need to have your images on the spot.
The invention of the Polaroid by Edwin H. Land in 1932 revolutionized photography. Even today, if you are fortunate enough to own a Polaroid camera and are able to get Polaroid film, you can still produce Polaroids.
Fortunately, we also have the Fuji Instax camera and film available. One of my favorite Lomography accessories is the Instant back that is available for the Diana F+ and the LC-A cameras. Very easy to install, and extremely fun to play with.
The advantage of being able to add the instant back to these cameras is that you can apply the experiments you normally would to these cameras (such as masks, splitzers, etc.), and obtain instant gratification.