title: Formatting strings into groups of 3 digits by periods
body: <p>I know I can format strings using the <code>String.Format()</code> method. Is it possible to format like this?</p>
  
  <p>Example:</p>
  
  <blockquote>
    <p>string: 1568<br />
       formatted: 1.568</p>
    
    <p>string: 168794521<br />
       formatted: 168.794.521</p>
    
    <p>string: 987<br />
       formatted: 987</p>
  </blockquote>
  
  <p>Sorry that I can't make myself more clear.</p>