NameserversTool.com - Nameserver Lookup Tool

DNS Checker Tool - Check Domain Name System (DNS) records for any website.

DNSInspect - DNS is a free online service to check your domain’s servers for common DNS and mail errors and produces a report with explanations how to fix them.

DNSChecker.org - Check DNS Propagation worldwide. DNS Checker provides name server propagation check instantly. Changed nameservers so do a DNS lookup and check if DNS and nameservers have propagated.

DNSQuerySniffer - DNSQuerySniffer is a system sniffer utility that demonstrates the DNS inquiries sent on your framework.

OpenDNS - OpenDNS provides faster and safer Internet access for your home or Business.