There is a file at
http://nadia.xiando.com/xiando-mu-plugins-2007-08-18.tar.bz2
This file contains xiando(tm) technology. You can experience the immensity of xiando technology friends list widget at http://eirin.trykker.com/ .. perhaps this technology may help you archive your goal.
It basically calls list_friends which is a function list_friends($FriendsOfUser, $tagBeginWrap, $tagEndWrap, $bLinkToBlog = true, $ShowPic = true, $pmLink = false, $lilist = false, $picsize = '16', $showname = true) {..}
The way persons website is figured out is:
$friendsprimary = get_active_blog_for_user($aFriendList[$i]);
get_active_blog_for_user will find the users "primary" blog (the first registered if they have more than one) and does not care what website address people put in their profile.
I fail to understand this "get it to link to a person's author ID number", what .. page / thing do you mean?
(Note that my friendslist stores friends by their *userid*, where is the friendslist you admit you're using stores their *blogid*, you're not adding a person as your friend, you're adding their blog)