An MSN Passport user name is the user's email address. An MSN or Hotmail email address is already associated with an MSN Passport with the same passwords. Most other email addresses must be given an MSN Passport manually; in which case the email address should (although doesn't have to be for all services) confirmed, and the password for the MSN Passport is not automatically kept the same as for accessing the email account.
An MSN Passport with limited functionality can be given without having an email address, although it is advisable to associate your email address with an MSN Passport.
Other online search sites such as Yahoo and Google offer their own equivalents to the MSN Passport, although these are less popular, particularly because of the popularity of MSN Messenger which requires the use of an MSN Passport.
To get an MSN Passport or learn more go to www.passport.net