This is AWESOME! Mark Caswell-Daniels has developed a little flight sim game which uses Google Maps to allow you to fly all over the place. You can climb, dive, turn and even crash! You also have the option of shooting things on the ground.
Now, what would be GREAT would be if he could turn this into a multiplayer game so that if you see someone else you could have a dogfight online in real time.
By the way, I also started another Web site called GoogleGames.org to catalog all the Google related games out there. Check it out when you get a chance.