At Cloudkick we use the hash bang on our new overview. The hash bang URI represents the application state or view. It is a UI tool that helps provides the user

At Cloudkick we use the hash bang on our new overview. The hash bang URI represents the application state or view. It is a UI tool that helps provides the user with an additional, browser friendly, means to navigate the application. The information in the hash bang is also private to the account and irrelevant to the public which can't access the same information. The URI portion without the hash bang is simply the application's address. The server doesn't need to know about application's UI, all it does is deliver the application. Many sites make the server part of the user facing application with server side templates and scripts but we are moving away from that. The UI will be in the client and server doesn't need to know about UI state. If your server is part of the UI then don't use the hash bang convention as the server can't make sense of it.