Finding Parts for Home-Made 'Bots?

Peter DeWeese asks: "For beginners in the field of anatomical robots, it is quite hard to find resources and shops from which to obtain small parts to build joints. Customized ball joints and a few other types are all that should be needed, and I am sure that others out there have built such machines from their own basements. Does anyone have any good resources on how to build/obtain small unarticulated mechanical joints that would be suitable? Please keep in mind that beginners often don't have metal lathes and high temperature welding torches."