Shoutbox

Best place to get that kind of info is:
http://www.passport.com/


EDIT: I don't mean to get .NET passport info from the users, but to contact Microsoft about using/implementing the .NET Passport service. As this isn't free, and you will have to pay for it (as it contains big privacy issues and stuff and all; it isn't given to anyone just like that)...

http://support.msn.com/eform.aspx?productKey=passport

or the address at the bottom of:
https://accountservices.passport.net/PPPrivacyStatement.srf