Well guys either my google fu / search fu sucks or I'm blind as I can't see if this has been mentioned on geekzone before.

I found about this tool called "namebench". It's a tool that runs on OS X . Windows and Linux that can be used to profile the DNS servers you can connect to.  Here's the download page :

http://code.google.com/p/namebench/

Here's the spec from the page :

"It hunts down the fastest DNS servers available for your computer to use. namebench runs a fair and thorough benchmark using your web browser history, tcpdump output, or standardized datasets in order to provide an individualized recommendation"

Had a go of it myself.  OS X 10.5.8 G5 iMac Isight (Oct 2005 edition 2.1 Ghz PPC G5 processor , around 1.5 GB memory).

App loads up pretty quickly. When I was running it ,  the tests didn't seem to drag down my computer that much running it's tests. Seemed to behave very nicely with the other apps I had opened.

Tried it both while actively using Firefox & World of Warcraft and then while not using the computer at all (I left it running while I ran down to Pak N Save). Didn't seem to effect it's results that much maybe a nanosecond out somewhere.

Presented a pretty neato summary of results informing I really should be using the Xtra 2 DNS server as my primary DNS , my modem router has secondary and some other one I can't really remember right now as I'm at Work right now away from the computer I ran the tests on.

Also profiels the response form OpenDNS and Google's new open dns service. Didn't seem to be a lot of difference between the various DNS servers TBH but your milage may vary :)

Here's the post I found it from.

http://www.macosxhints.com/article.php?story=20091207221026406

I'm kinda keen to test out this new fangled topic replies email messaging system our illustrous admin put in so comment away please !