What are the pros and cons of using an email address as a user id?

Question

I\'m creating a web app that requires registration/authentication, and I\'m considering using an email address as the sole user id. Here are what I see as the pros and cons (upd

Answer 1

As a user of websites, I can tell you that I hate memorizing unnecessary usernames. I don't use a unique handle or anything so I can never remember which variation of my name I used that wasn't already taken. I'd much rather type my email address.

Also, I like OpenID.