The other thing you can set is a regex that deletes stuff from URLs. I use it to remove session IDs and stuff from URLs so they get conflated together. Whatever matches to the regex is deleted from the URLs that pass the exclusion regex above. Also, remember we only track URLs that have a referer, so this really isn't a log analysis tool...
The third regular expression allows you to select lines that fit the previous two criteria based on the HTTP status of the request. It defaults to ".*" so all lines are considered. You might want to change it to 200 or 2.. to get only successful lines, or 304 if you only want to see who is getting request denied. (Might be fun if you run mod_rewrite and deny people access to images based on referrers or something.)
An example of how I have the options set up is shown below. Notice that I escape the "." in the regular expression, and have some crap deleted from URLs. The GUI for this could be much better also, I'm sure.
Options are saved every time they change, but do not take effect until a re-start of LogWatcher.