As I recall there were people selling thin strands of gold laminated to cards at a past porcfest. I don't remember the min denomination though and you would have to trust the weight they say.
Yeah it's just another form of trust based exchanges. And if you are going for trust based exchanges you can go debt based and be able to expand the supply to meet the demand.
The advantage of bitcoin is that you only need to trust public/private key, no miner controls 51% of the mining power & you aren't experiencing an extremely powerful and sustained sybil attack.
