If you do Google Adwords advertising, this is a page you'll want to put on your bookmarks. Markus Allen is tracking the 250 most expensive keywords on Google Adwords and updating the list each month.
Click on the image below to see the full list. I am floored by the Cost Per Click for some of these keywords.
Do you think you could learn something about conversion from people who are spending over $100 per click to get people to their sites? They have to have high converting landing pages or they'd work straight through their advertising budget in a day or two with nothing to show for it.
Track down the advertisers without clicking their Adwords links though. They are paying a pretty penny per click and you don't want to run up their bill.