An idea one preventing exchange manipulation like we've just seen.

Currently it seems like the exchanges are the weakest link to BTC and if any one exchange ever gets as large as Gox did again, then history will repeat itself.

I honestly don't know if this would be possible, as I am not a programmer myself, but would it be possible to change the BTC protocol to track the prices people are trading at?

Say, the blockchain is changed to also track how much each btc is being traded for (with a weighted average). The exchanges would then pull their pricing data from the network instead of keeping track of their own. This would also make all the markets even, more stable, and if DDos'd (whether malicious or a bank run) it would not effect the overall price by much.