Change currencies through BitCoin or other Cryptocurrency I'm from Brazil and I'm going to USA in January, so I need to buy dollars.
Here in Brazil every currency exchange done have to pay a tax that is usually 7%.
But we don't have to pay that tax in cryptocurrency. 
So i was wondering if I can do it through Bitcoin or other cryptocurrency.


First I would buy Bitcoin in Brazilian currency to my wallet through any exchange (Real to Bitcoin)
Second I shall sell this Bitcoin in any exchange that accept USA Dollars. (Bitcoin to Dollar)


But I don't have anywhere to keep this money. 

Have anyone already done this in any currency? 
Would you describe how you've done it?
With no bank account: You can buy Bitcoin in your home country then sell them for cash in person in the US through sites like Local Bitcoins once you get to the states.

With large sums of money its good practice to wait for six blocks on the blockchain before considering the transaction confirmed.

With a bank account: Non-U.S. citizens are allowed to open a bank account in the United States. You can wait to open a bank account in person when you arrive or try opening a bank account in your home country at a bank that operates in both your home county and the US. (In Brazil HSBC is one example of a bank that operates in both counties). 

To sell your Bitcoins get an account at an exchange like Coinbase or Circle, trade your Bitcoins for USD there and connect that with your US functional bank account to withdraw the funds.