If you're baffled by the possibilities of an uncertain future, and can't decide which stocks to buy, don't dust off your Ouija board just yet. We've found a better way to invest for the long haul.

Exchange-traded funds (ETFs) are a cross between stocks and mutual funds. From broad-market indexes to small sector niches, each gives you instant, and often inexpensive, exposure to a select array of stocks. That simple diversity can be a big help when you're having trouble finding the most compelling companies.

Suppose you're bullish on health-care stocks, but can't decide which individual companies to buy. Consider a sector-specific ETF such as Vanguard Health Care (VHT). Its 300 holdings include Amgen (NASDAQ:AMGN), Express Scripts (NASDAQ:ESRX), and Johnson & Johnson (NYSE:JNJ).

That said, a little indecision is still healthy. Before you plunk your money in, you'll want to take a closer look at this investment. In one promising sign, Vanguard Health Care's expense ratio is a very modest 0.25% -- a little lower than its sibling Vanguard Health Care (VGHCX) mutual fund (0.33%), and much lower than Fidelity Select Health Care (FSPHX) at 0.86%. 

You might also be interested to learn that despite its hundreds of holdings, the ETF's top 10 stocks comprise roughly half of its value. That means the remaining half is divided between 290 other companies. Top holding Johnson & Johnson alone represents 11% of the fund. Even if you're OK with that, you'll still want to know before you invest.

Meanwhile, in other nooks...
Exchange-traded funds can rescue you from indecision in lots of other ways:

  • Interested in the blowout power of emerging markets, but too skittish to venture into Chinese or Brazilian companies on your own? Consider the Vanguard Emerging Markets Stock (VWO) ETF, whose bigger holdings recently included Israel's Teva Pharmaceuticals (NASDAQ:TEVA) and China's CNOOC (NYSE:CEO).
  • Want a basket of solid dividend payers for your portfolio? Try the iShares Dow Jones Select Dividend Index (DVY), with holdings such as Lorillard, Kimberly-Clark (NYSE:KMB), and Clorox (NYSE:CLX).
  • Tempted by precious metals or commodities, but don't know where to start? You might put a small portion of your money in the PowerShares DB Commodity Index Tracking Fund (DBC), which will quickly give you positions in gold, silver, corn, soybeans, and more.
  • And for the very indecisive investor, there's the Vanguard Total Stock Market (VTI) ETF, which plunks you into the entire U.S. stock market. You'll be a part owner of just about any U.S. stock you can think of.

Those are just a few examples. An ever-expanding roster of ETFs covers multiple regions of the world, such as Sweden, South Africa, and Latin America, as well as many industries and niches, such as biotechnology, consumer products, retailers, financial institutions, and software.

With so many bargains filling the market after 2008's market crash, you owe it to yourself to do some exploring. If you're not sure which specific stocks most deserve your money, ETFs can offer an easy way to end your indecision and start investing.

Exchange and trade further fundamental Foolishness: