Think the U.S. economy is bouncing back big time? For a simple and inexpensive way to get in on the rebound, invest some money in Industrial Select Sector SPDR (XLI), an exchange-traded fund, or ETF, that's an all-in-one portfolio of 60 industrial giants, including General Electric, UPS, 3M, Boeing and Lockheed Martin. State Street Bank, the ETF's sponsor, assembled the bluest of the industrial and transportation blue chips and weighted the portfolio by the stocks' relative values. GE makes up about one-fourth of the mix. UPS is next, at 8 percent.

That kind of convenience is why we love ETFs. There are 125 of them, including entries from Vanguard and, soon, Fidelity. Competing sponsors have christened their ETFs iShares, SPDRs and VIPERs, but they all work the same way: You invest in a stock index, an industry, a foreign country or region, or in a theme or style — such as those industrial blue chips.

There are no sales fees, and ongoing expenses are tiny, occasionally less than 0.1 percent. Your major expense is trading costs because you buy and sell ETFs just as you do stocks.

What other ETFs can you get? If big industry isn't your bag, buy the broad market by allocating 75 percent to iShares S&P 500 index fund (IVV) and 25 percent to iShares Lehman 1-3 Year Treasury (SHY) for balance.

While the S&P 500 is fine, ETFs are great for slicing and dicing indexes.

For example, small, growing companies are humming right now, and you'll find them in iShares S&P SmallCap 600/Barra Growth (IJT). The 225 names in this ETF include homebuilder NVR, Panera Bread and Florida Rock Industries.

For the broadest reach in the strong health-care arena, we suggest iShares Dow Jones U.S. Healthcare Sector Index Fund (IYH). Half of your investment goes into companies such as Pfizer, Johnson & Johnson and Amgen, and half into scores of smaller biotechnology and medical-products firms.

Regional Bank HOLDRS (RKH) is an ideal way to invest in the country's best regional banks, a group that has lagged in 2003 but over time provides steady growth and juicy dividends. You get 18 major banks in one fund, including Wachovia, Bank One, U.S. Bancorp and Wells Fargo.

Finally, if you're pining for a faraway land, ETFs of Australian (EWA) and — would we lie? — Brazilian stocks (EWZ) are having nice runs. Instead of spending your money on a vacation, this is a longer-lasting way to enjoy Brazil.