The peso isn't the only undervalued Mexican currency. Mexicana Airlines' Frecuenta mileage program can help you travel the world in business or first class for a fraction of the normal price.
You don't even have to set foot on a Mexicana plane, according to Matthew Bennett of Firstclassflyer.com. That's because you can buy frequent-flier miles from Mexicana for a bargain 1.6 cents each (on other carriers it's more than 2.5 cents) and use them to fly airlines like American, Air Canada, Air New Zealand, Singapore and Lufthansa.
Here's how it works. Say you want to fly from Los Angeles to Tokyo first class on Singapore Air. By buying 120,000 miles at 1.6 cents, you'd spend only $1,920, vs. $12,565 for a typical fare. There's no limit to how many miles you can buy, but it can be difficult to find frequent-flier seats, so check availability first.