Before you begin thinking that this is an awesome trick to play on your co-workers (and it is), there actually is a legitimate use for this "feature". Developers can use this trick to artificially creat a memory dump for testing purposes. But it's much more fun for Linux and Mac evangelists to "demonstrate" how fragile Windows can be. Once you enable this feature, you'll be able to create a BSOD at any time by pressing a certain key combination on your keyboard.
Read more at OCModShop.