Network domain lookup and diagnostic tools:-
..: Domain suffixes
..: Dig it man! Get DNS data on a domain.
..: IP locator Find the location of an IP address
..: Another IP locator
..: Whois lookup, Africa
..: Whois lookup, Asia and Pacific
..: Whois lookup, Northern America
..: Whois lookup, Southern America
..: Whois lookup, Europe
..: NetNames - Domain Management Services
..: Check multiple DNSBL listings.
..: Another DNSBL database check
..: Nominet Domain registry for all .uk
..: Netcraft What's That Site Running Check web site configuration.
..: Domainmonger A quality domain registration service.
..: DSL speed test (requires java)