This seems like a great time-waster idea. It would probably be very addictive if it ever got critical mass. Naturally I think it will be impossible to monetize on its own, but it will be awesome when a profitable company buys them out.
Cool idea, but I don't think the terms and conditions would allow it. You're not allowed to embed them directly into an application. A HTML page that the application displays that is accessible from any browser should be OK, but you'd lose the 'sense' part. Maybe ads for the most popular sites, with specially created HTML pages with hidden text (if Google overlooks that, which I doubt) that guides the adsense, would work.
It has been a while since I looked at it - I was pondering building a consumer app supported by adsense but decided it was probably too much trouble.
