Savvysource.com is a great resource. There is such a demand for preschools in San Francisco. I have been applying since my Son was 18 months old and am still on waitlists. Most of the schools are giving places to siblings and that seems fair, except that it is making it hard on first time parents. Anyway, we visited another school last night (the Little School) and really liked it. Halfway through the presentation the Director, explained that they are full for next year already but we were welcome to apply just in case. There were 60 parents at the "open house' and at $100 per application and then not to get in, seems like a bit of a scheme. I have applied for 5 schools and so far, no luck. I was very fortunate last week I heard through the grapevine of a new school and I called and they had one place left and my son got it. I am very happy with the school. It is Presidio Pre school on Sacramento street. It is small which is what I wanted for my son. They seem to care, it is a playbased school and the staff are very ethusiastic. You should contact the school and meet with them. Starting age is 2 years and 6 months and they take kids in Diapers.
I am now starting to apply for Kindergarten. My son isn't 3 yeat. Isn't that ridiculous? Good Luck.
Y.