Casa Lucas Market (Number 2, the first one is in San Francisco) is a pretty cool Latin American market on East 14th in San Leandro. As you would expect they have a large selection of Mexican products, but they also carry an eclectic selection of other Latin American products. It's a relatively small store, so their selection /is/ limited.
I usually go there to buy empanada shells (tapas para empanadas), they also have a nice selection of yerba mate (including in little bags) and a few canned jams and Savora mustard, for some reason. They only have small jars of dulce de leche, though. They did have Havana alfajores (no habannets, though), at $1.60 each they are expensive (about 3Xs what they cost in Argentina) but ooooh, so good.
Anyway, in today's trip I was able to find cassava (manioc) flour which I need for my Bahian meal (they also have white & yellow corn flour, rice flour and even banana flour) and guaraná soda, a very typical Brazilian soda. They didn't have malagueta peppers, however, so it's a good thing that I got these in LA. I also don't think they have palm oil, but I didn't look closely.
I did find ají amarillo sauce, an essential ingredient of Andean cuisine. I'd already bought some in LA, but it's good to know it's available here. They had a few other Andean sauces.
They also have Colombian sodas, Venezuelan arepas and Central American products. They have a good variety of (cheap) fruit and vegetables.
Casa Lucas Market
16684 East 14th St.
San Leandro, CA 94578
510-317-5750/51
Oh, for those who care, the owners seem to be religious. Their business card says "Christ Saves" and they were playing Christian radio (in Spanish) in the store.