To turn an Address Book contact into an online contact

In the Contacts pane in Outlook Express, right-click a contact, and then click Set as Online Contact.

–or–

In the Address Book, double-click the name of the contact, click the Online tab, click the contact's e-mail address, and then click Set as Online Contact.
If you select the contact's Hotmail address, the person will be added to your list of online contacts.

If the contact does not have a Passport or Hotmail address, the Add a Contact wizard starts, allowing you to send the contact an e-mail invitation that explains how to get a Passport and install the messenger service program.