About the searchword database:
This is how I made a top-10 list at my site. (quick and dirty)
I modified the script that showed the latest searches that I have posted earlier.
(The minimum modifications needed are that the script outputs every line in the log.)
Save the output, and use a texteditor with "text statistics" to count the words.

A more elegant solution would be to have a perlscript to automatically generate
the list from the database, but since I don't have that much traffic yet, I have not
thought it was worth the effort. (Maybe later...)