Have you ever seen this? It's faux lilliputian photography via Photoshop.
Now, of course, you couldn't use this for a close up shot. Better for landscapes which I don't take much of, but still something I'd like to try out someday. A neat idea for an engagement shoot might be to take a far away shot of the couple in the middle of a carnival and make it look like they were miniature train-scale models.