I would like as simple as possible a registration and login process. Should I use a username or an email address as the key identifier during the login? (Presumably the user db might also a user name AND an email address (and a unique ID number, first and last name, etc) - my question is just for the login and registration.
Thanks,
JDelage
PS: For those interested in this question, it was asked on the webmaster QA site, but the angle here is different (see http://webmasters.stackexchange.com/questions/3096/user-registration-forms-do-we-need-a-user-name).