You can give keywordspy a try.

KeywordSpy.com is a Keyword Research Tool that helps identify what keywords competitors use, with results actually reflecting what advertisers are using at the current time. - http://www.keywordspy.com
michelle | Homepage | 10.11.07 - 4:45 am | #

I just stumbled upon this page and wanted to mention that Chitika works great for me! Over the last year I compiled some statistics of my earnings and I actually earned twice as much with Chitika compared to AdSense. For those of you considering Chitika - try it! You can check out this Chitika review for some more info.
Tom | 02.29.08 - 3:34 am | #