Strobist info: SB-900, camera right, bare, triggered with PocketWizards (MiniTT1 w/AC3 & FlexTT5).
This was my first attempt to do this kind of shot, and it was very much rushed because the sun had already gone down and I wanted to get it done before the sky got any darker. If I had more time, there's a few things that I would have tried to do better. This idea is of course borrowed from others - specifically one of my flickr contacts that did a similar shot. I don't remember exactly who it was, but if it was you please post a comment and give yourself credit for inspiring me.
This is two separate shots, taken from a tripod and layered together in Photoshop. The background is identical in both shots. The first shot had Abigail standing on one foot on top of her car. The second shot was without her or the car. Then I just had to layer them on top of each other and "erase" the car from the top layer.
Post-processing done with Capture NX2 (w/Color Efex Pro 3), and Photoshop CS5.