San Francisco's homeless may lack a permanent address, but some of them are getting free lifelong phone numbers and voice mail, courtesy of Google's Grand Central telephony service and Mayor Gavin Newsom's Project Homeless Connect (PHC).

Newsom launched the social program on Thursday at the Bill Graham Civic Auditorium in San Francisco, along with a California Pacific Medical Center initiative to provide homeless women with mammograms.

"Providing phone and messaging capabilities and access to vital health care is an extraordinary step forward in the city's commitment to a comprehensive approach to addressing the needs of this vulnerable community," Newsom said in a statement. "Housing our homelessness residents remains my top priority, and providing these services will certainly improve their quality of life and empower this community to be more self-sufficient."

PHC, an outreach program designed to assist people in the transition from homelessness to housing, began operating in October 2004. The organization's model has been exported to more than 100 cities across the United States and in other countries.

Grand Central's effort to provide phone and voice mail service predates its July acquisition by Google. The startup began operating Project CARE (Communications and Respect for Everybody) in April 2006.

With free phone numbers and voice mail, homeless Grand Central users will be able to record greetings and check messages from any phone. Google, in conjunction with the mayor's office, plans to make its service for the homeless available throughout San Francisco's homeless shelters.

In a blog post on Thursday, Craig Walker, senior product manager of voice products for Google, extolled the transformative effect of technology. "We're firm believers in the power of technology to improve the daily lives of individuals and communities as a whole, and we recognize that access to phone and voicemail services is one way that Google can help San Francisco's homeless stay connected with family, friends, social workers, health care providers, and potential employers," he said.

Officials with Google and PHC are hopeful other cities will adopt the Grand Central service to assist homeless people in their metro areas.