title: CSS Footer Fixed Width, Bottom of screen, and centred
body: <p>I'm an iPhone Developer mainly, I'm a bit rubbish at CSS and I'm trying to make a webpage for my app.</p>
  
  <p>I want to make my footer have the following properties:</p>
  
  <ul>
  <li>Fixed width of 640px</li>
  <li>Centered</li>
  <li>Attached to bottom of <strong>screen</strong>, not page. So when the user resizes the window, the footer is always at the bottom</li>
  </ul>
  
  <p>All the other styling I can do myself, it's just positional styling that I find really difficult.</p>
  
  <p>Can someone please explain to me how to do this in just CSS.</p>