Google yesterday announced winners of the Android Developer Challenge, which put up US$10 million in prize money to developers of the best applications for its nascent mobile platform. In doing so, Google also helped to stock the shelves of Android Market, a forthcoming online retail site for Android applications akin to iPhone's App Store.

Development teams of the top 10 applications each received $275,000, the 10 next-best applications got $100,000. Another 30 applications were recognized as finalists.

Many of the top finishers employ location-based services of some kind. There's GoCart, which uses the phone's camera to scan a bar code while you're shopping and then price-compares like items from nearby stores and online retailers and provides inventory data and user reviews. Compare Everywhere, a similar product, also helps manage shopping lists. An extremely clever app is cab4me, which combines GoogleMaps, GPS and cell data to hail a cab to your location with just one button-press. No phone call, no directory assistance. You don't even need to know where you are.

It's remarkable that an operating system released only last November has spawned so many great and useful applications, especially when they involve technologies as complex as mobile cell networks, global positioning and the restrictions of embedded programming. The first phones to use Android, which is Linux-based, could be available to consumers as early as October, according to an August 14 report in the New York Times.