Play It Safe: Agriculture

From a passing car, a vista of rolling farmland looks serene, safe and, well, a little boring -- and investing in agriculture can induce the same feelings. Prices of food commodities, such as wheat, corn and pork bellies, have been on an upswing during the past decade, and many analysts believe they'll keep rising, as China, India and the rest of the developing world get richer and eat more. Of course, investing in just on ag product can make for a bumpy ride. (Don't get us started on that 30% dive that lamb prices took back in '08.) The good news: Agricultural commodities trade fairly independently of each other if one is down, another might very well be up so investors who own several can get more predictable returns. The Market Vectors Agribusiness (MOO) exchange-traded fund owns a little bit of a lot of things, and since its inception in 2007, it has gained an average of about 7% a year.

Go for Broke: Rare Metals

Investors have gotten used to the idea of owning gold, but other rare metals are downright exotic by comparison and even riskier. Take uranium, whose role in nuclear power makes it a potential winner in the quest for cleaner energy and whose value pogos with the price of oil. If you'd bought your sweetheart a lump of the metal for Christmas in 2005 (not a great idea, by the way, since it's radioactive), its price would have quadrupled over the next 18 months, to $136 a pound, then fallen back down to $41 less than two years after that. Lithium, another "green" metal and a favorite of battery and electric-car makers, is just as much of a roll of the dice. For those with strong stomachs, Global X Funds recently launched ETFs focusing on each one (tickers: LIT and URA). The funds mostly own mining companies, says Morningstar ETF analyst Abraham Bailin, but their prices should still soar or fall with the fortunes of the moody metals.