Maybe you've heard about Youtube's harem shake trick, but this is a little bit different and i think everyone should try it. This computer trick is interesting even after the harlem shake addiction but however it's a nice trick and you can just try it from curiosity or from being bored. Ok, let's get into it.
First to do is going to paste bin's site: http://pastebin.com/HZfEQzQF to copy the code containing the actual trick. After copying that you need to open Mozilla Firefox (you can do this into other browsers but this tutorial is made for Firefox because i think it's easier) now just right click on your website and click on inspect element or just press the "Q" button on your keyboard and a little window will appear. Then you need to go to the console tab (it's first) and there paste your code. Now just wait some seconds and watch the party!