Reverse 911 on your cell?

Many people have given up their land lines, and are depending completely on cell phones these days, but the reverse 911 system doesn't call cell phones. I heard that bit of information somewhere yesterday, and it seemed a compelling reason to keep a pretty pink princess phone on your nightstand (other than the obvious reason that it will make you feel like a princess. duh.) Today the UT has posted on their fireblog that you can register your cell phone to receive emergency alerts on the City of San Diego emergency website, however the county just installed their system over the last few months, and that functionality isn't set up yet.