I have always been fascinated by the visual effects of Tilt-Shift photography, creating the illusion of looking at a model on a real world scene.
The iPhone has a great app for doing this easily without having to invest in expensive tilt camera equipment. To create an illusion of scale you need to pick a scene with large and small objects and ideally photograph from a high point looking down on the scene. With the inclusion of strong colours the model world effect really takes shape.
The image below was taken on top of Warwick Castle looking down on the street below. Taken with an iPhone 4 and TiltShiftGen app.
Great fun and a nice twist on your average vista.