Now that Twitter has a geo-enabled API, we think there are a number of interesting ways that BlockChalk can interact with the Twittersphere to everyone’s benefit.

We’ve just started our first experiment, which is to collect chalks from two U.S. metropolitan areas (New York City and the San Francisco Bay Area) and then send them to Twitter in real time. In addition to geographic coordinates, these tweets include hashtags representing the neighborhood and city where the chalk was written, and a link enabling you to read the entire message over at BlockChalk.

You can find these tweets at @BC_BayArea and @BC_NewYorkCity, with more cities coming soon. And since they’re geotagged in Twitter, you’ll also see these tweets when you use your favorite geo-enabled Twitter client in these two areas!