One of Outlook’s most astonishing omissions–which is in no way remedied in version 2007–is the lack of a way to go directly from a contact to a printable envelope. My workaround is pretty good, although not as pretty as I would like. I just create a folder called ‘Envelopes’ inside my My Documents/Business Files directory and organize envelopes by lastname, firstname.doc. I then attach those to my contacts using the attach files feature.
It works fairly well, although I still think it is ridiculous that Microsoft has not yet seen fit to give us a direct link from contacts to envelopes.