title: Routing for custom ASP.NET MVC 404 Error page
body: <p>I am trying to make a custom HTTP 404 error page when someone types in a URL
  that doesn't invoke a valid action or controller in ASP.NET MVC, instead of it displaying the generic "Resource Not Found" ASP.NET error.</p>
  
  <p>I don't want to use the web.config to handle this.</p>
  
  <p>Is there any kind of routing magic I can do to catch any invalid URLs?</p>
  
  <p><strong>Update:</strong> I tried the answer given, however I still get the ugly "Resource Not Found" message.</p>
  
  <p><strong>Another update:</strong> Ok, apparently something changed in RC1. I've even tried specifically trapping 404 on an <code>HttpException</code> and it still just gives me the "Resource Not Found" page.</p>
  
  <p>I've even used MvcContrib's resource's feature and nothing - same problem. Any ideas?</p>