Hi Sarah!
Welcome to the forum...
How long a ride do you normally do? Do you have any routes you particularly like?
I work in the richmond district, but work weekdays. I sometimes take rides after work, but nothing particularly long since I have to get home and of course be energetic enough for the rest of the week. My normal loop takes me through the park, along the great highway (or 48th) sometimes then up vicente to west portal area and then home. It could be fun to ride together sometime, but I am only available after work on Mon. & Tues.
I'm intrigued by the velogirls' ride and such (as you might be), but things outside of the city can sometimes not be so convenient, especially when dealing with traffic.