White Pages in Windows/Active Directory

I was wondering if Microsoft had some type of web based white pages
functionality built into Windows 2003/Active Directory? I thought about
using Exchange 2003 and the GAL. I know you can customize a user's
properties and add a tab along with fields such as phone number, room number
or anything else you want.

I have a friend who is a Novell administrator and they have a product called
eGuide. It stores user information such as room number, phone number,
address and other information about the user. It is like a white or yellow
pages phonebook.

Thanks in advance,
Jim