[megri]

I have come across a Google Contextual Ads Preview and Comparison Tool. You just put URL of the page and this tool will tell you what kind of ads will appear on your site. It shows all formats of ads available at Google Adsense including image ads

http://googleadspreview.blogspot.com/

They call it Digital Inspiration Contextual Ads Preview Tool - Yahoo YPN vs Google Adsense vs Chitika