title: pip install PIL doesn't install into virtualenv
body: <p>How do I install PIL?</p>
  
  <pre><code>&gt;pip install PIL
  
  Downloading/unpacking PIL
    Could not find any downloads that satisfy the requirement PIL  
    Some externally hosted files were ignored (use --allow-external PIL to allow). 
  Cleaning up... 
  No distributions at all found for PIL 
  Storing debug log for failure in /root/.pip/pip.log 
  
  &gt;pip uninstall PIL
  Can't uninstall 'PIL'. No files were found to uninstall.
  </code></pre>