Google isn't taking Apple's iAds initiative sitting down (actually at Google IO, they are having all kinds of fun tweaking Apple), they're showing off more interactive ads right now - ads that aren't necessarily even Google ads, they can be served simply via Doubleclick (or whomever). Adsense for mobile apps has been offered to everybody at the Google IO conference with $100 free advertising credit.

The new ads can ads that send you directly to a mobile app, movie previews, "expandable" ads, do click-to-call directly, and more.