The Department of Emergency Management in San Francisco has set up a service to provide warnings and instructions during and after disasters. AlertSF will deliver text messages in English or Spanish to e-mail accounts, or devices such as a cell phone, texting pager, or PDA. The service is expected to be offered for free, but prior sign-up is required. This is obviously a good idea, assuming that wireless network will remain operational during the disaster.
The service is later expected to be expanded to provide more alerts such as traffic delays, power outages, road closures, and other important information
[ via CNET News.com ]