You guys seriously need to do your research and start getting your facts right. 
[size=8pt]THE MUSLIMS DO NOT, I repeat DO NOT THROW FREAKIN' STONES AT THE DEVIL FOR CRYING OUT LOUD. They throw stones at pillars that represent him! [/size]DUH. If you don't believe me, google the damn thing. Or just read this passage from the BBC (http://news.bbc.co.uk/1/hi/world/middle_east/4180965.stm#map)

In the morning, pilgrims return to Mina and throw seven stones at pillars called Jamaraat. These represent the devil. The pillars stand at three spots where Satan is believed to have tempted the Prophet Abraham.

And that, is also your answer mr who wanted to find out.