title: What is "loose coupling?" Please provide examples
body: <p>I can't seem to grok the concept of "loose coupling." I suppose it doesn't help that the word "loose" usually has a negative connotation, so I always forget that loose coupling is a <em>good</em> thing.</p>
  
  <p>Will somebody please show some "before" and "after" code (or pseudocode) that illustrates this concept?</p>