This is a video by George Selgin about the private coinage in the UK just before and during the earlier stages of the industrial revolution. Is one of the best conferences I have seen about monetary history, and the bitcoin community can get some very valuable lessons from it.
The whole video is full of them, but as I was watching it again one struck me: when the system became widely accepted, in spite of government trying to impose its money monopoly, the shops would demand double price if you wanted to pay in government money. Thats how much they valued their private coins. It was the government money that was rejected! I believe the same thing will happen with bitcoin once it gains some traction.
The obvious question is: if this coins were so popular and so useful why did they disappear? Fair question, and the answer is at the end of the video. And this is why bitcoin is such an incredible system, because it would have avoided the fate of this private coins because of its characteristics.
http://www.youtube.com/watch?v=-gn55fTRXZwPS: Anyone knows how to embed a youtube video?