In Exchange 2003 if you wanted to access OWA internally it would be the http://Exchange_Server/Exchange . An administrator could go to the deault web site properties and on the home directory tab you can select a "a redirection to a URL" to /exchange so you can use short URL e.g. http://mail to resolve to the above URL.
In Exchange 2010 it's https://cas_server/OWA. Is there a procedure to create a shortname URL so users can simply put in https://mail or something like that so they don't have to remember the longer internal OWA name?