Why are there different prices for bitcoins between exchanges? Ive been looking around at the prices for bitcoins at various different exchanges and they all seem to have slightly (or wildly) different prices, why?

Thanks.
Economically speaking, this can only happen if the expected cost and risk in arbitrage outweigh the expected profit. Arbitrage, in this case, would be buying coins on a cheap site and selling on an expensive one. The risk comes from the high volitility and long confirmation time. In the hour or so it takes to transfer the coins from one site to the other, it's very possible that the price could have dropped enough that you end up losing money. The  aforementioned risk is why no one has tried to take advantage of the price differences and (as a result) equalized the price.