If you're bullish on the global economy, currency ETFs offer plenty of opportunities. Your best bet is to go global.
Many experts like the CurrencyShares Australian Dollar Trust because of Australia's close ties to China and its sizable commodity exports. The WisdomTree Dreyfus Brazilian Real Fund is another popular choice.
China has been keeping its currency in a narrow range, and while its economy is slowing, there is still growth.
Anthony Davidow, a portfolio strategist at Guggenheim Investments, sees opportunities there "if you have a long time horizon and an appetite for risk."
If you prefer a play on emerging markets generally, there are basket ETFs that serve that purpose. Tom Lydon, chief executive of Global Trends Investments, recommends the WisdomTree Dreyfus Emerging Currency Fund..