I'm not sure how easy/hard this would be to make. It would be a really cool feature though!

I was looking at making it myself, but I'm having trouble getting a hold of the required google adsense code

http://code.google.com/apis/custom-sear ... rator.html

You can use the html widget and just paste the generated code for now (haven't tested it), I too was thinking about creating such a widget. Perhaps having it so you can just drag and drop it where you want with no editing options on the widget itself, but within the widget administration part perhaps applying all the "setting information" for google adsense. Let me know if you decide to take on this.

-Jules