Comcast's gigabit internet access doesn't officially go live until sometime in 2016, but that isn't stopping the company from flicking the switch a little early. The cable giant recently activated what it says is the first public-facing DOCSIS 3.1 cable modem in the world -- a fortunate customer in Philadelphia now has the kinds of speeds that previously required at least a partial fiber optic link. There are additional tests running in parts of Atlanta, northern California a