If you are evaluating 3rd party DNS, I developed a tool for testing recursive dns query latency here http://cloudharmony.com/dnstest - the test covers most major Anycast providers.
<b>Fatal error</b>: Call to a member function getAffiliateOrStandardUrl() on a non-object in <b>/var/dropbox/deploy/cloudharmony/lib/util/CH_SpeedtestUtil.php</b> on line <b>802</b><br />
[17:16:45.352] speedtest is not defined @ http://cloudharmony.com/js/run-speedtest.js:144