Use Firefox for this. It would be cool if you could center it somewhere more local than SF. It’s also pretty buggy right now.
It was based off a a Mario Kart application that can be found here.
Anyway, my idea for the coolest thing ever would be to bring back the Mario Kart racers into this, and allow you to drive around towns in Mario Kart!
And now for even cooler yet non-realistic ideas: This could be integrated with Google maps to incorporate street view and terrain. The game could also be multiplayer. The point is, the information is there and the technology is there. How cool would it be to race Toadie and Yoshi around Philadelphia’s City Hall? Imagine playing battle mode in the streets of Boston!
Ooo, and you could incorporate live traffic too, it could get kind of Toad’s Turnpike-esque!