Boy, nothing like realizing that one of your sites has not been serving up content for almost 2 months. The site is 'up', but any queries into it returned nothing. Very useful for a lookup/reference tool. :-/
One of these days I'll get a monitoring system in place that's more advanced than "Is the server up?"
Aren't you using Nagios for monitoring? We could surely write an appropriate customized script to make sure it was actually returning content....