When is __proto__ useful?
<p>When is <code>__proto__</code> useful?</p>

<p>A lot of browsers support it, but because not all do, programmers seem to be scared of using it. I've never seen it in any code (such as the libraries jQuery and backbone.js).</p>

<p>When is <code>__proto__</code> useful? Is it just a geeky thing for completeness?</p>
