Didn't see anyone mention it, but keep this dynamic in mind when speculating on Mt. Gox price movements:
If events happen which restricts Mt. Gox's ability to convert BTC to fiat funds for bank transfers, then there is a rush to buy BTC so that they can be transfered out of the exchange to somewhere that has less banking restrictions - price on that market goes bump.
If liquidity is foretasted to improve - whereby it looks like it will become easier to convert BTC to liquid fiat, then there will be a short term selling spree on that exchange and prices will fall as pent up need to extract fiat is fulfilled.
Growing pains of a very young market - don't be discouraged.

There is logic behind all the movements even if it's mostly just driven by popular news releases.... Wish i worked in the bitcoin news industry - they must be making a killing in buying and selling before news breaks.... Just like in the old non bitcoin world i guess....