How to run PHP files without uploading them to a server

OK, maybe the title is a bit misleading. You don't have to upload them, because you turn your own computer into a server sort of. The files are not really accessible anywhere other than your own PC.

1. Download and install a free program called WAMP
2. Once it has been installed, you can place any files into the WWW section of your wamp installation. You can access this by clicking on the wamp icon in the system tray and clicking 'www directory'.
   
3. You can also use mySQL, which means you can do everything you could have done online.