I was curious about the search terms folks might be using to search my site, so I dug up a script from the ht:/Dig contributors area called toplog.pl and modified it a bit so my template would be embedded in the output. Then I wrote a little shell script that calls toplog and creates a file using the current date - my shell script is in turn called by a regular cronjob.
(There's also a way to see the search terms that led visitors to this site - the terms are reported in the httpd logs)