I prefer to use the Forms authentication for most of my applications. And most of my projects consist of a few relatively independent parts running on subdomains of the main domain. It would be nice to have single sign-on, so if you are logged on at www.example.com, you would be recognized also at everything.example.com. Forms authentication by default does not support this feature, but is not too complicated to tweak it the appropriate way. Read More . . .