Timbuk2 San Francisco: Timbuk2 makes bags for Northern California urbanites. They build sleek, durable, and fad-proof, usually in muted colors that hide stains well. Their luggage is light, and designed for hard use.
Glaser Designs: San
Francisco-based Glaser makes luggage to order for
"executive travelers," which I think means wealthy professionals who
spend a lot of time on planes.
Aer: San Francisco-based Aer fills a very specific niche. They make luggage for carry-on plane travel. In addition to carry-on-sized travel bags, they sell packing cubes, which are designed to organize and compress clothing to maximize usable space.
Honorable Mention -- Away: Away is from New York, not from California. For people who never stop traveling, however, Away is a Blue State company whose luggage deserves to be considered.