Export profile data as VCard

With the _user() hook, it would be easy to add a link to the user profile page which let you download another user's info into your address book.

The standard mechanism for exchanging user info is VCard, and I know that PHPCollab uses this class - http://www.bitfolge.de/index.php?l=en&s=phpvcard

This is especially useful on intranet sites where email and mailing addresses are not private.