
I know this is an AP feed article but it would be really easy for a CC Times reporter to do a local angle on this, and it can be fun if he or she is also single. For example the Lafayette-Orinda Presbyterian Church used to host a great set of non-religious singles groups and I see at http://www.lopc.org/singles_organizations.asp that they are still supporting them though don't seem to be hosting the groups directly.
It's likely that other leftist leaning churches (Christian Science, Presbyterian, Quaker, Unitarian Universalist, and Unity) also have single groups that will feel welcoming regardless of your personal religious beliefs or feelings. The good news is that church sponsored groups and events tend to be low cost (the church provides the meeting space) and low key as people are not sitting around and getting boozed up. Meetings often have some sort of activity, a lecture or board game for example, that allow you to interact with others without, gasp, really needing to *talk* to them. :-)
There are many charity organizations in the area and they always love to have extra bodies to help with their projects. As the goal of a get-together is a service project it can be much more comfortable for those not into the “meet someone and get laid” scene common at bars or commercial singles organizations. An example that comes to mind is the Animal Rescue Foundation (ARF) on the Concord/Walnut Creek border which has a wide range of volunteers from young teens to seniors. There are gardening clubs and if you like books it looks like you can volunteer at your local public library.
City recreation classes are another low cost option. You can either take classes or work or volunteering in them and will be bumping into people that share at least one of your interests.
Remember to be friendly to people much older than you as they tend to look out for and after the younger people (you in this case) and are likely to know of local groups where you can hook up with people that share your interests. They tend to also be looking out for a nice guy or girl to hook up with one of their younger relatives.