[wintermute306]

No one likes registering for anything, that is pretty well known.

Getting users to do this though is part of my job and my job is often made easier either by auto-fill options in browsers and good form design.

URL based autho systems are pretty limited in their applications as anything on the other side would have to be of little importance. The security implications of such a system are massive...What if you need to log into an account and you use a work computer? Surely all someone needs to do is press ctrl-h(or access server logs) and visit the same url to gain access to your information.