Passion Play Investors looking to expand their portfolios are putting their money where their hobbies are.

In five short years, the price tag on Larry Sirolli's loft apartment in Manhattan has skyrocketed 70 percent. But what's hanging inside his home represents his most impressive purchase: a late 1950s abstract expressionist painting by American artist Stephen Greene. Sirolli purchased the piece at an auction in Chicago for little more than $1,000 in 1999. Today, he estimates it's worth $60,000--a whopping 5,900 percent gain.

No amateur to the art world, Sirolli, 47, boasts 23 years at Sotheby's and one year as owner of New York City private art dealership and consulting business Sirolli Fine Art, which has brought in sales of $1.3 million so far. However, his investment play is becoming more commonplace. Individuals who once focused solely on stocks and bonds are diversifying into so-called "passion investments" like art, wine and even NASCAR.

This year, high-income families will place 22 percent of their assets in these alternative investments, according to Capgemini and Merrill Lynch, up from 10 percent in 2002. Experts say the appeal is both monetary and emotional. "Psychologically, you don't get that attached to bonds and shares," says Mahesh Kumar, author of Wine Investment for Portfolio Diversification. "But a 1982 Chateau Margaux--people take pride in that." Investing in a Jeff Koons or a cabernet can be a gamble, however, so be sure to research and diversify.

If wine is your passion, choose investment-grade vintages, which offer more longevity and liquidity--and profits of about 15 percent over a 20-year period, according to Kumar, whose wine portfolio has grown nearly 60 percent over the past three years. He recommends first-growth wines from Bordeaux, Burgundy and Tuscany, which can start as low as $5,000 for a few bottles.

Wine investment funds, mainly based overseas, offer another route. Diversification eases the risk, but funds usually charge steep fees and require a minimum investment often in the tens of thousands.

Race car fans don't need as much to spin their passion into an investment. The StockCar Stocks Fund (SCARX) requires a $250 minimum investment and offers a broad portfolio of stocks linked to NASCAR, from sponsors to dependable Dow names like Exxon Mobil. Since its launch in 1998, SCARX has returned about 8 percent annually. Says fund manager Robert Carter, "It's a way [race fans] can invest in a fund that supports [what] they're interested in."

Art has long been a favorite passion investment. But one big risk with investing in art: Artists can fall out of style. "There were artists [who were] hot 10 years ago that are stone-cold now," says Michael Connors, owner of the Michael Connors Gallery in New York City. For added protection, buyers should research the gallery or auction house promoting a given artist. "There is some art out there that's not very good, but it is being marketed so well that it [appears] hot," says Connors. Of course, if you're not an insider to the art world, differentiating the "hot" from the "not" can be tricky. Do your homework, and speak to art consultants and appraisers.

Don't have $50 million to plunk down at auction? You can start with a few thousand. "Try to find the best of a lesser-known artist," says Sirolli. That was his approach when he bought the Greene. Now, however, he's fallen victim to an unexpected risk--getting too attached. He admits, "It's hard for me to part with it."