title: Retrieve contents of URL as string
body: <p>For tedious reasons to do with Hpricot, I need to write a function that is passed a URL, and returns the whole contents of the page as a single string. </p>
  
  <p>I'm close. I know I need to use OpenURI, and it should look something like this:</p>
  
  <pre><code>require 'open-uri'
  open(url) {
    # do something mysterious here to get page_string
  }
  puts page_string
  </code></pre>
  
  <p>Can anyone suggest what I need to add?</p>