Knowbot is a "master directory" that contains email address
information from the NIC WHOIS database (Whois), the PSI White
Pages Pilot Project, the NYSERNET X.500 database and MCI Mail. Most
of these services are email registries themselves, but Knowbot
provides a very comfortable way to access all of them in one place.
Telnet to nri.reston.va.us on port 185.