displaying that info publically might not be a good idea. it's possible that they were referred from their webmail, or a site that they don't want people to know they were on. more of a privacy issue. it was more meant for me to know where my new users were coming from. but how you use it isn't my choice
i definately need a better way to display the data in the admincp, .. or maybe modify some templates so only administrators can see that info on their profile age.