In the case some of you find yourself at Dolores Park I might have to recommend the Sunny Vibrations food truck.
I stopped by last weekend and got the vegan sausage with peppers. I know it looks pretty basic, especially considering all the gourmondo options surrounding the park, and it is... Sliced wheat bread, peppers, onions, marinara and Tofurky sausage was the total sum of this sandwich... but the idea behind this truck is pretty rad. Everything is cooked fresh and the energy supplying the whole operation is the solar panels on the roof of the truck.
Also, a great perk, while waiting for your food there is a hand-held massager - which my park-going cohorts took full advantage of. I can't think of any other place I've been to that offers massages while you wait!