Assuming two people get together to make this happen is reasonable. It's also reasonable that two other people will get together and do US<-->BTC and another two peple will do BTC<-->BRL. That gives you the 'path' to make the remittances automatic. My point was there really doesn't need to be a cross border transfer at all - simply wait until someone builds another gateway to return the debt.

For people sending money home to Brazil, well, they don't have to know anything about Bitcoin to make this work. The network just takes care of it.

I love the postage stamp analogy! Great post man.