BlockChalk is an anonymous message board for your neighborhood. The company's founders want to enable neighbors to interact with each other while protecting everybody's privacy. At it's core, BlockChalk feels a bit like an anonymous, location-based Twitter clone.

BlockChalk just released its native iPhone app (iTunes link) today and also offers an app for the Palm Pre and Pixi. Android users can access the service through a mobile website.

Anonymity Makes for an Easy Setup

Given that BlockChalk is completely anonymous, you don't have to sign up for the service or jump through any hoops before you can get started. Simply start up the app, allow the service to access your location data and you can see what others around you are saying. BlockChalk works worldwide and has active users in over 90 countries.

Features

BlockChalk keeps its feature set light and to the point. Besides posting your own messages, you can browse replies to your own posts and respond to messages publicly and in private. On the iPhone, BlockChalk also supports push notifications.

By default, BlockChalk doesn't reveal a user's exact location. You can, however, force the service to do so by typing [here] in a post.

One of the company's co-founders, Stephen Hood, used to run the product team at del.icio.us and some of the same design aesthetics shows in BlockChalk. The design is simple, to the point and doesn't get in the way of the product's features.

Anonymity: Good, Bad or Just the Best Way to Get People to Share?

While using BlockChalk is a lot of fun, there is also something strange about the anonymity of the service. On the one hand, it will surely encourage those users who would otherwise be afraid to reveal their location to use the service. On the other hand, however, this could easily encourage vandalism. BlockChalk offers a profanity filter and the ability to "bury" posts, but only time - or an attack by 4chan - will tell if this will be enough to discourage disruption.