Transparent wallpapers

It's amazing no one thought of this LONG before.
The idea is simple, take a picture of anything at a certain angle, set it as your laptops wallpaper, then take a picture of the laptop in that same angle! Not sure what I'm talking about? take a look at the picture below and you'll get it!
For more creative pictures like that one (all mac though), head over here.
I'll try to make my own one day. It seems it's a craze that's catching on!