You can almost hear the loudspeaker: "Attention all investors. The party is moving overseas." Economists these days are pounding the table with conviction that tomorrow's big growth will come from outside the U.S., most notably places like China, India and Brazil. Moreover, there are now 262 mutual funds and 143 exchange-traded funds (ETFs) that invest exclusively internationally, according to Morningstar. So how should you approach this opportunity? "It's all about asset allocation, not chasing performance," says Tom Idzorek, chief investment officer at Ibbotson Associates, an investment-research firm owned by Morningstar. For example, he notes, the stock market outside the U.S. is now larger than the stock market inside the U.S., which suggests that young investors should put more than half their portfolio outside the U.S. That may sound radical but, says Idzorek, "the best trade-off of risk and reward comes when your portfolio mirrors the world stock-market capitalizations." Of course, as people get closer to retirement, the risk of currency swings becomes more of a concern, so the percentage invested overseas should come down then. But even at that stage, retirement advisers recommend anywhere from 20% to 40% of a stock portfolio be invested internationally. Diversified, actively managed mutual funds offer an attractive way to invest abroad because you can hand off the task of following world economies to a professional. People working with investment advisers, on the other hand, may want to cherry-pick the most promising markets. Nathan Bacrach, a financial adviser with Financial Network Group in Cincinnati, likes to use unmanaged ETFs to give his clients niche exposure. One he favors is EWZ, an ETF that invests solely in Brazil. "This is a progressive democracy that is energy self-sufficient. What's not to like?" he says.