Exactly my suggestion. My commute is an hour each way but I work from home on Thursdays and will soon work from home on Tuesday as well. You should talk to your employer. They will most likely understand. If they don't, leave and go somewhere that will. It's a good time to be a Ruby developer in SF, so you have some leverage there.
I already do work from home 1-2 days a week, however the other days it is still a lot of time out of the day.