Possible to use "Real Name" instead of Username?

[Jabong82]

Is it possible in Vbulletin for users to have their real name as userIDs instead of some made up username? That way when they post in Forums their real name is shown instead of some made up name (just like a facebook or myspace etc)

Can we register them with real names?

Basically in the registration form, we would change "username" to real name, but I would think Vbulletin would have a problem because obviously two people can have the same name and it wouldn't allow it.

Is there any way around this? I know that we can allow people to use their email to login, but I don't see how I can get around the duplicate usernames.

Thanks in advance.