Iain, bless him, keeps downloading funky new iPhone photo apps for me to play with. This shot was taken with an app called Camera+. In this app, unlike Hipstamatic and Camtastic, you add the processing after you've taken the shot, so you can experiment with different effects. However, for this particular shot of our neighbours' wool shed I had the effect I wanted in mind before I took it.
The 'tilt shift' effect adjusts the depth of field so that the subject looks like a model. Click here for some cool examples of tilt shift photos. Tilt shift works best if you take the shot from above the subject, and if the subject is in the centre vertically. I decided to take the shot at midday (usually the worst time for taking landscape shots), so that the light would be coming from above, as it would if this really were a model.