Today, while looking into the new Google Maps Docs, I ran across the Styled Maps. They are quite powerful! While Cloudmade offers a similar service for a while, I didn’t expect Google to offer this, and for free.
A bit of technical background: these mapping services work by splitting the world into tiles. The whole world takes millions of tiles (depending on zoom level), and thus hundreds of gigabytes to render and store. While rendering and storing the world once isn’t that much effort for Google, rendering it in as many styles as it’s customers come up with does take quite a bit of processing power (For more background on the subject: See my Thesis on LBS)

While I have run a tile render server in the past, this was always an expensive, and not that scalable operation. So I’m suprised (but happy!) that Google now offers this to the world, for free! In just a few minutes, I was able to create the demo Waterworld shown above.

More examples can be seen on the Google Maps blog