Whatever you do, don't be tempted to buy any gold because you will be 'thumped' en-route or at your final destination. American Express might do nicely though ;o)
I tend to find, that in my travelling days, the US$ in note form as a better valued exchange rate. I always use to carry a few of those bills about, and was never refused on any of my travel arrangements, where in some cases £sterling was looked on with some suspicion and a jumpy exchange rate. But perhaps times have changed, since all those years ago?.