I read an article on Boing Boing the other day about a technique called "tilt shift", it's basically a method for creating a lens blur to mock depth of field on an image that wouldn't normally have it. For instance, this photo has a strong depth of field to it, of course it does, it was taken with a macro lens from a few inches away. But let's take a look at an aerial photo, then apply the tilt shift method, and ta-da! It's suddenly a small cardboard model!

Here are a couple of different photo I have tried this with.

march2006 photography tiltshift