The second part is harder because there is another key to open-source sharing: the cost of distribution, which is negligible. Clearly, for physical goods there will always be a non-trivial cost component. However, there are still plenty of semi-virtual goods out there that could work, including radio frequencies, computer processing and bandwidth (eg. SETI).
Key quote in all of this: “Social sharing [represents] a third mode of organising economic production, alongside markets and the state.”