Do a search for sites that are "powered by wordpress". If you find sites with adsense, you'll at least know it's possible.
Edit: Actually it would be easier probably to just through the sites on WordPress.com » Get a Free Blog Here I went through a few and didn't see any adsense but I did see ads so there must be some way to use plugins?? And if so, you should be able to use the the adsense plugins.