[eluser]Kemik[/eluser]
Hello,

Do you use usernames to login to your apps, allowing the change of email addresses (but the email must be unique) or do you use email addresses to login to your apps, allowing the change of usernames?

I'm faced with that dilemma for my new project. Half of the current "like" sites use email as the identifier and allow users to select their own username. As long as the username is unique they allow the change via their "edit profile" page. The user's email can also be changed but must be unique, however email is used to login.

The other half of "like" sites, mainly forums such as vBulletin, PHPBB, etc use usernames. Usernames in these apps cannot be changed, the emails can.

So, what system do you use and why?