Okay, let me have an opinion about bitcoins then:
The basic idea of a digital currency is quite good. I appreciate such new technological approach. There has never been a better time to do this now since so many people trust the internet again.
However the implementation is completely wrong or at least destined to fail. Why? It’s like stock market, but even more speculative. How come? Anyone can create bitcoins but there is a limit in the whole amount of bitcoins, which the inventor set to roundabout 21 million bitcoins. A real currency is not bound to any certain limit. Instead goods (e.g. Gold in the national bank) or economical strength define how much a currency of a country or currency union is worth.
Since so many bitcoins (BTCs) have been created, it’s impossible to gather more coins than the set limit. So what happens now is the price for each coin will rise. But what happened during the last days is something that nobody would have expected that soon: BTCs got lost / stolen (nobody knows, what really happened at Mt. Gox). The trust in this currency is non-existent for many people who wanted to start investing.
China had some impact on the BTC value, too. The Chinese government had forbidden any conversion from BTC to Renminbi (Chinese currency). That day BTC’s value dropped by 40%(!) which is according to the value of one BTC a lot. It was due to the fact that 1 billion of possible interested people dropped to zero (according to public opinion, there might be still some people left).
That means in conclusion: I wouldn’t trust that digital currency. As long as it’s so easy to manipulate the value in short terms, I wouldn’t recommend investing in this market and therefore paying with this is insecure for both customers and shopkeepers.