Land, as Scarlett's dad advised in Gone With the Wind, is the only thing that lasts. He might've added that while real-estate prices fluctuate, the asset class provides a great diversification tool in an investor's portfolio. Today's Five Winning Funds highlights some choice mutual fund offerings in the real-estate category. More than any other sector -- including tech, all you momentum lovers -- real-estate funds deserve a place in most investors' long-term portfolios. The category has been a great performer over the past three years. So far in 2002, real-estate and real-estate investment trust, or REIT, funds are up 12%, according to Lipper, a Reuters company. The category has turned in three-year annual returns of 13.4% on average and five-year annual returns of 6.13% on average, according to Lipper. The S&P 500, meantime, is down 10.32% a year over the past three years and down 1.35% a year over the past five years. Of course, that doesn't mean investors should be jumping into to real-estate funds looking for a quick shot. The sector has been hot, and the hefty dividends offered by many of the funds have kept them buoyant. But as Real Money.com columnist Chris Edmonds notes, economic concerns weigh on the office property group, apartment markets look overbuilt in most areas and valuations are a concern. But the reasons for getting a piece of real-estate funds aren't short-term in nature. Over the long haul, real-estate funds have provided diversification, leading to greater returns and reduced risk levels, according to asset-allocation consultant Ibbotson Associates. Real-estate funds are especially appealing because of their low correlation to the broader market. REITs moved in tandem with large-cap stocks only 55% of the time from 1972-2000, and the correlation level dropped to 25% from 1993 to 2000, according to Ibbotson. Comparing returns from certain years drives home the point. In 1977, the S&P 500 fell 7.2% and REITs rose 18%. While owning real-estate funds in the late 1990s would have crimped an investor's returns by a few percentage points, over the long haul, real estate has been a boon for the balanced portfolio.