Problem is unstable rate of bitcoin so you wouldn't want to hang on to them in storage, you'd need a way to buy them on demand by either leaving USD on Coinbase

Problem is unstable rate of bitcoin so you wouldn't want to hang on to them in storage, you'd need a way to buy them on demand by either leaving USD on Coinbase account or having #bitcoin-otc IRC trade open, Stellar might be more suited for this you could create UruUSD coin when it gains more adoption https://stripe.com/blog/stellar https://stripe.com/blog/stellar