I know what you mean about finding strange phrases in your server logs. To figure out what page they’re landing on (and possibly turn those phrases to your eventual advantage) try installing a plugin called slimstat.

With this plugin, when it tracks the link, you’ll find the details of where the traffic came from. I wrote an article called How to Increase Web Site Visitors For Relevant Terms Using Your Less Relevant Listings that gives you the steps to turn the searches to your advantage. You can find it at ezine articles or Google it.