title: How to control who uses my web widget
body: <p>I've created a web widget that displays user specific information from my site. This widget is java script based (I followed <a href="http://emphaticsolutions.com/2011/01/21/functional-widgets-with-rails-javascript-jsonp.html" rel="nofollow">this example</a>), and can be embedded in other sites.</p>
  
  <p>I'm looking for a way to control who can embed the widget in his site. Any ideas/references are welcome.</p>