This past weekend, adventurous developers were invited to participate in the Cleanweb Hackathon , a competition that challenged entrants to develop apps in just 24 hours--everything from Chrome plug-ins to cell phone applications--that allow users to use natural resources more efficiently. One of the more intriguing winners of the hackathon was Freshlist, a text-based marketplace designed to help people buy and sell produce in real time.
Created by Hoa Huyn and Freshr  founder Joshua Rosen , the app uses the Twilio  API for text messaging to easily allow people to make transactions. "I came up with the idea around 1 p.m. on Saturday, but I've been working in the agriculture space and looking at building online marketplaces for buying and selling fresh produce," explains Rosen.
Here's how the marketplace works: A buyer texts their inventory (say, 20 apples) to a list of buyers. A nearby buyer types "list" and gets a list of everything being sold in the area. The service uses GPS to locate buyers and sellers, so nearby produce is highlighted. When a buyer is ready to make a purchase, the seller receives a text with the buyer's phone number and deletes their items from the inventory list.
Rosen imagines that marketplace could be used by restaurants, farms, and even individuals. If someone has some extra lemons falling off their backyard tree (a common occurrence in San Francisco), for example, they could sell them through the app (though various government agencies might have something to say about that). "The next step is building this into a more robust platform," he says.
Freshlist was just one of three entries to win awards at the hackathon. The others include Team TACO, which developed a Google Chrome extension that publicizes the lifetime cost of ownership (including energy) of a product on a retail website, and Dr. Wattson, a web app using the Tendril API that offers suggestions on reducing your energy bill and rates.
[Image: Flickr user Half Chinese ]