I'm pleased to say I'm a member of this timebank. For people in the Bay Area wanting to promote local economy and also gain education and experience in currency independence, I highly recommend SF BACE.
In particular, the website is easy-to-use, and I've found the online community is very friendly and full of offered products/services.
I also recently attended an educational event presented by BACE organizer Mira Luna - the experience was very insightful. This is definitely a well-oiled and professionally run operation.