Elmah and MVC - 404 and 403 access and permission errors

I've said it before and I'll say it again - I love Elmah. But today I had trouble getting it to work with my latest MVC project which is due for launch. It took some googling to find out exactly what the problem was, and I had to piece together hints and tips from across the web. So, in short, take the latest Elmah.dll and drop it into your bin directory. Add this line to your RegisterRoutes method in Global.asax.cs:

routes.IgnoreRoute("elmah.axd")

Then you need to configure your webconfig file like my gist on github. Just look for all the 'Elmah' bits and do the same. Then visit http://yourserver/Elmah.axd and you'll see your error logs. Cool huh?