There are a variety of ways to play emerging markets. There are broad funds, such as iShares MSCI Emerging Markets (NYSEArca: EEM), Vanguard Emerging Markets (NYSEArca: VWO) and iShares MSCI EAFE Index (NYSEArca: EFA).
There are funds that focus on regions, such as Claymore/BNY Mellon BRIC (NYSEArca: EEB) and BLDRSAsia 50 ADR Index (Nasdaq: ADRA).
Finally, there are single-country funds, such as iShares MSCI Brazil (NYSEArca: EWZ) and Market Vectors Vietnam (NYSEArca: VNM).
Keep in mind that the narrower you get in your exposure to emerging and frontier markets, the higher your risk will be. Be sure to have an entry and exit strategy before you invest. (How to follow trends).