If you've got a WordPress Site/Blog or a Squidoo lens or... that's been up for a couple of weeks or months and you need more traffic, look at your analytics!
Squidoo has a display of the keywords that brought visitors to your site, and google analytics or ClickTales does the same. Even your AWStats in your Cpanel lists all the searches that brought people to your site.
PEOPLE SEARCH FOR THE DAMNDEST STUFF!
These 'off the wall' long tail search terms will never show up in any keyword program, but if the same one shows up a few times in your analytics, it's time to target that keyword!
They're also really useful to see HOW people are finding your site so you can either target those search terms more effectively, or in turn, re-evaluate your SEO efforts if the searches are not relevant to your goals.
Hope this helps somebody,