Billionaire investor Wilbur Ross, who has made most of his money restructuring failed companies in such unglamorous industries as steel, coal, and most recently, textiles, is not the kind of guy to jump on the latest technology fad. Therefore, when someone like Ross begins investing in nanotechnology, I believe it serves as further validation that the technology is moving into the mainstream.

Yesterday, I had the opportunity to hear Ross deliver a keynote presentation at the sixth NanoBusiness Alliance conference in New York City. In his talk, he explained how he pretty much stumbled into nanotechnology when he acquired Burlington Industries, a textile manufacturer, in a bankruptcy deal a few years ago. As part of that deal, he also acquired Nano-Tex, which Burlington then owned.

Nano-Tex has successfully been incorporating its nanofibers into a variety of stain-resistant garments, including many from Brooks Brothers, Adidas, Eddie Bauer, and Lee Jeans.

The technology itself was enough to catch Ross' attention, but what really made his financial antennae perk up was its tremendous growth potential. In 2007, Ross estimates that nano-enabled textiles represent roughly $11 billion in sales. By 2012, he expects that figure to jump to $120 billion.

This growth, in turn, caused Ross to direct his investment team to scour the landscape for other such nanotechnology opportunities. As a result, he has made sizeable investments in five other private nanotech companies in the past year.

What caught my attention -- and what I think should interest to Foolish readers -- is that four of the five companies he selected are already in Harris & Harris' (NASDAQ:TINY) portfolio. For the record, those four companies are Neophotonics, C-Switch, NanoOpto, and Nanosys.

My point here is that Ross is not a venture capitalist. He is a practical, experienced businessman with a great nose for turning around companies. If he's investing in nanotech, it's not because he thinks it's a fad, but because he thinks there's great value in these companies.

Most of us don't have anywhere near Ross's financial resources. But if you agree with him that there is real substance to nanotechnology, an investment in Harris & Harris represents an excellent way to piggyback on his investment expertise.

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Fool contributor Jack Uldrich is the author of two books on nanotechnology, including Investing in Nanotechnology: Think Small, Win Big. He owns stock in Harris & Harris. The Fool has a strict disclosure policy.