By Inc.com

Looking for a hot stock? How about a company whose revenue has shot from $455,000 to $68 million in three years? Or from $209,000 to $24 million in three years? Or $662,000 to $40 million in three years?

You don't see revenue growth like that often from companies trading in the stock market. And, in fact, these companies are not publicly traded, at least not yet. The three -- Cedar Point Communications, Genoptix Medical Laboratory and Santur -- are ranked Nos. 2, 4 and 12, respectively, on this year's Inc. 5,000, a list of the fastest-growing private companies in the U.S.

They're also the top three on Inc.'s list of 100 companies that intend to go public, so savvy investors will want to keep an eye on them. Genoptix, for instance, has already filed for an initial public offering.

For more than 25 years, the Inc. 500 -- beefed up this year to the Inc. 5,000 -- has been the home of future household names. Microsoft (MSFT, news, msgs), the publisher of MSN Money, made the list in 1984 at No. 80, when the world learned that the company's revenue had grown 1,969% between 1979 and 1983. Microsoft made the list again in 1985 and then went public in March 1986. Now it has a market cap of about $275 billion, and its annual revenue has gone from $50 million when it first made the Inc. list to $51 billion last year.