Ever wonder what new prank you could come up with to make your little sister go crazy? Here's a simple, yet very effective one. Just switch one of your desktop icons (i.e. Internet Explorer) with a fake one and a warning box will pop-up which will shut down your computer within 30 seconds. Isn't that enough to make lil' sister yell when she sees her Barbie doll game go bye-bye? Here's how it works: