I thought I was getting poor response times from my site but a friend then pointed me to http://www.websitepulse.com/help/testtools.website-test.html
which allows you to test your server response time.
It reported the following for me:
Test performed from: Munich, Germany
Test performed at: 2007-05-24 08:09:30 (GMT -04:00)
Status: OK
Response Time: 2.056 sec
DNS: 0.506 sec
Connect: 0.040 sec
First byte: 0.499 sec
Last byte: 1.010 sec
Size: 15181 bytes
Does that seem a reasonable set of figures? The DNS looks a bit on the slow side to me and the First Byte time seems rather slow too.
Re-running it got the DNS time to a slightly lower value but the first byte time was still high