Determine which transaction output is a change address and which is not Is there a way to determine which transaction output is a likely a change address and which is not?

Looking at this transaction, there are two outputs - a change address and the output address. Blockchain.info says "Estimated BTC transacted: 0.5 BTC", but I'm not sure how it's estimating that.
You can guess at which output is a change address, but the only way to be certain is if you are the person initiating the transaction. 

In fact, some wallet software could be designed to intentionally obfuscate this data, to improve user privacy. At best, services like blockchain.info can only guess.