There are always willing travelers/tourists who need to exchange money, it would be a good idea to advertise on localbitcoins.

you have the pesos, they have BTC, good trade.

The best way of course is to mine, after all, If you have a good used video card it is time to start mining; Do not mine litecoins! you will earn far less than just mining BTC directly at this moment.

If you mine with a 5870 for a month you will earn guaranteed 120 USD. if you mine litecoin it will be 40 USD.

Then distribute the BTC to the people for the calculated cost of inflation and your exchange fee. NO illegalities, no hassle, just time and a little effort.