Enabling cross-domain calls for SL apps on self-hosted TCP services

On a post a couple of years back, I showed a solution to enable cross-domain calls for Silverlight apps on self-hosted WCF services. In Silverlight 4, we added a new transport (net.tcp), which needs its own policy file as well (see more details at http://blogs.msdn.com/b/silverlightws/archive/2010/04/09/policy-file-for-nettcp.aspx). If you are running IIS (or some other web service) on port 80