DNS zone response speed test tool?

I've put monitoring onto my public website, and by far the largest component of the response time it gives me is the DNS lookup -- 4-500ms, which seems entirely unreasonable. Is there a tool that anyone knows about that will measure the response time of my zone servers, somewhere on the web? Is the sum of the times in a dig +trace the proper metric to look at there? Cheers, -- jra -- Jay R. Ashworth Baylink jra@baylink.com Designer The Things I Think RFC 2100 Ashworth & Associates http://baylink.pitas.com 2000 Land Rover DII St Petersburg FL USA http://photo.imageinc.us +1 727 647 1274