Google is using its GrandCentral service to offer free voice mail to San Francisco’s homeless population. Signing up for the service will give them a local telephone number that they can forward to any number they choose (if one is available) and that is associated with a voice mail box that they can check from any phone line. This service is already freely available to anyone who can sign up online, but it’s great to see Google specifically going out and offering it to the homeless. They stand to benefit more from the service than people who already have phone lines, and there’s probably very little chance they would even find out about it otherwise.