QuintinBonsai
Chumono
Daiso Japan, which are basically Japanese dollar stores located mainly in California. Amongst the many rows of nick-nacks, they do have a small selection of products usable for bonsai. I found large colanders, soil sifters, soil scoops, and even drainage netting. Many thanks to John Kohler of GrowingYourGreens.com for introducing these stores to everyone.