Thanks to Yola, I’ve just discovered the exact iPhone application that I’ve been looking for! Enter: California Farmers’ Market Finder.

It does everything that I want to in a farmers’ market app: sorts by day, locates the markets nearest me, plots them on a map — and it does it for the entire state! Thanks PasoTours!
In fact, based on these guys’ blog, it appears that we had the same idea around the same time.