Not sure how much froyo will be on the minds of people with the seasons changing to the cooler, but Tuttimelon is now open on the corner of New Montgomery and Howard.
This is a self-serve location - they had original, mango, almond, pomegranate, and blueberry; all seemed nicely tart save for the original (which seemed somewhat bland to me) and they're all touted as probiotic. They also had a good (but not over-extensive) selection of fruit and other toppings. Gelato is also available.
The shop itself is on the lower level of one of the more recently built condos in this area, and has a small amount of seating inside. The young lady inside was very helpful and insisted that I sample all the flavors before I got to producing my froyo construct.
My cup came out to under $4, which based on the volume I got seemed about in the price range for this stuff.
There are so many froyo shops in this general area, but if you like any of the Tuttimelon locations around where you are, you'd probably be perfectly fine coming by here if you're in the mood.
199 New Montgomery (corner of Howard St)
San Francisco, CA