Thanks.  Those threads are definitely of interest.

Reading them made me realise that a really good application of this idea would be to build a distributed altcoin exchange.  Altcoin exchanges are essential because trading from BTC into an altcoin and back is almost like the zerocoin concept, so long as the exchanges are black boxes.  Imagine a distributed exchange that replicated itself with the profit!

The obvious weakness here is that people with physical access to the hardware can steal its wallet or manipulate the software, and it would be easy to trick an autonomous agent into purchasing a VPS from you for this purpose.