A OneBayArea Travel Map we worked on with the good people at MIG, Inc. It shows you approximately how far you can get from any point in the Bay Area by car, public transit, bike, or on foot, at particular times of the day. You can filter your view by the travel time between areas, and the median price of homes in each area.
Here's where you can get from Stamen in the morning, by public transit (Muni and BART), within 30 minutes (all of these images link out to the right configuration of the maps btw):
Your range is limited much further in the evening:
It turns out that you can get a lot further by bike. Note how the time of day doesn't matter here because bikes aren't limited by transit schedules or traffic congestion: