The trick is very simple: you just take a shot of what's behind your screen and make it your desktop background. And yes, I've tried it, and yes, it's more difficult than it looks to get it just right, especially if you don't have a laptop.Just imagine when a friend will come to you and he will look at your laptop, or at your PC, and will see this. It's hard to make it look good, but in the end it looks really nice.