We've just added Categories! Now it's easier than ever to use BlockChalk in your neighborhood to borrow, trade, buy, sell, complain, praise, report, and connect. BlockChalk is the voice of your neighborhood. Use your mobile phone to leave messages on your block, your street, at the coffee shop, or anywhere you happen to be. Respond privately or publicly to messages from people in your neighborhood. It's easy: you don't even have to sign up.