I think the current view of how bitcoins are going to used is purely transaction based, at least for the short term. So when you when you want to buy something you convert your local currency into bitcoin, exchange it with someone else, then they convert it back to their preferred form. Doing it this way also protects against the bubbles/crashes that are bound to come, as the fluctuation in price between the two conversions should not be too much.

Theoretically there is no maximum price but its worth as much as people are willing to pay for it. I think 3/4 price bubbles have been predicted to develop before mining finishes in around 10 years. It is still early days but like it is said above if no-one is trading or spending them then they will be worth virtually nothing.

Try running it with this command line

python poclbm.py <account username>:<account password>@pit.deepbit.net:8332 -v -w128 -f 2 --device=0 --platform=0 --verbose

What version of poclbm are you using. Try running python poclbm.py --help or -v to find out the version. I  read somewhere else that if it is the beta version it might give you that error.

Get the latest version from here https://github.com/m0mchil/poclbm and see if that works.

I set up a machine to mine. A couple of weeks later got a payout of 2 shiny bitcoins.

As long as you have a backup of your wallet.dat and your pool is setup to payout to one address generated from that wallet then you own any bitcoins paid out.

This would still cause them to go from confirmed back to unconfirmed for a while though.

Probably only going to be a problem if it happens with malicious intent right?

Purely down to implementation in my opinion. The core bitcoin protocols are theoretically very sound it is how they are used at the moment that are the problem eg... MtGox hack( under protected wallets ). If you are not a technical person it can be very hard to take the steps necessary to protect your wallet from theft either local or remote which can means that people cannot trust the system fully.

Oh yeah and also virtually no one accepts them as payment so even if your wallet is fully secure its gonna be hard to find anything to do with them

What are the possible implications of parallel block chains developing. For instance if a country or significant subset of people got isolated for a substantial period of time, they would surely start work on their own block chain. When this isolated group was then reconnected to the rest of the network then, assuming that they did not hold the majority of the processing power, the block chain they had been working on would be destroyed and all transactions placed in that time lost.

This may be unlikely to happen but if it did then:

How would it be detected, as the bitcoin client only has a handful of connections to other nodes and does not need connections to every other node so a decrease in the total nodes available would not really be possible. Looking at how bitcoin tries to find other nodes there would probably have to be some malicious activity involved to keep fake irc/dns records but may be possible through 'natural' causes.

If this did happen and the resulting lesser block chain was valid. How would these transactions be recovered if at all possible?

This doesnt sound beyond the realm of possibility and if isolations happened often( malicious or natural ) then this would surely seriously affect the reliability of any bitcoin transactions placed.