http://host.com/?form- works for the whole sitehttp://host.com/path/?form- works only for /path/How common is to have the same login form in multiple places? - Lwn.net in its articles (/lwn/article/####) has the same form, you would have to put your login every time for every article - Google accounts? - Twitter (and other RoR sites I believe) has: + /login/ + / + /sessions/new/Path based logins allow you to have a user in /admin/ and another one in /login/. This is a *workaround* for fixing multiple users per site.