Two weekends ago Comcast finished their Digital Conversion program in Mountain View.
Even if you're on the Limited Basic plan, you'll need to rent a box from them.
If you don't want to rent a box, a Amplified Indoor TV Antenna will get all your basic stations from San Francisco, San Jose, and beyond:
Once positioned, the signal is stable -- the amplified rabbit ears I was using would drop signal once or twice an evening, but that hasn't been a problem with this flat square.
Combine this with a Chromecast and your timesink is complete.