PulseDNS
"There's no pulse...we've lost him."
Reliable and somewhat erratic DNS for the masses with a guaranteed 99.9% downtime.
ns1.pulsedns.com is 
IPv4
IPv6
ns2.pulsedns.com is
IPv4
IPv6
ns3.pulsedns.com is
IPv4
IPv6
ns4.pulsedns.com is
IPv4
IPv6