The Internet has proved to be a democratizing force, harnessing the power of community to help the everyman research topics of interest, find a new book that's right up his alley, and even learn to be a better investor.

Take Wikipedia, for example, where users pool their collective expertise while helping to police content, creating an encyclopedia with more breadth, depth, and nimbleness than old-fashioned Britannica could hope to build. Companies that cull user recommendations and reviews such as Digg and even seek to capitalize on the same spirit.

No crowd control in alternative energy
Motley Fool co-founder David Gardner, on other hand, is most interested in using community to help us all become better investors. Last February, he tried an experiment -- tasking Motley Fool Rule Breakers members to help select the service's next two stock picks. The only parameters: Nominees had to be working in the field of alternative energy. That's because David believes alternative energy is a disruptive technology on the brink of a 10-year bull-market run.

That belief's not hard to substantiate.

Is it getting hot in here?
As this year has worn on, there's been increasing attention to climate change, along with the idea that it's time for both consumers and corporations to act. (A recent Wall Street Journal article said that the first half of 2006 has been the warmest in the United States since recording began more than a century ago, while Newsweek ran a recent special section on going green in America.) The buzz is getting louder.

Need more indicators beyond changing consumer attitude and media headlines? President Bush chastised Americans' "addiction" to oil in the spring. Big oil companies are increasingly looking to hedge their bets by investing in alternative energy plays. BP is a prime example, having doubled its investments in alternative energy; it's also forming a unit dedicated to its low-carbon power activities. Venture capital was also at a four-year high in the second quarter of this year, and one of the industries benefiting was energy -- with increased investment in alternative energy start-ups.

So why didn't David pick the stocks himself? Although he had identified a wide market opportunity, he was hoping others could help him hone in on the best technology in the vast field.

The merits of the masses
And the experiment was a success. The community bubbled up a fascinating number of investing ideas and generated a windfall of interesting and thought-provoking discussions on the topic. The members ultimately decided on one stock and one exchange-traded fund (ETF), PowerSharesWilderHillClean Energy. The fund offers a diversified way to benefit from some of the brightest stars in the alternative and renewable energy universe, instead of concentrating funds on smaller firms with uncertain paths to profitability.

Consider its recent top holdings, some of which you may not even have heard of: SunPower (NASDAQ:SPWR), Kyocera, Cypress Semiconductor, OrmatTechnologies (NYSE:ORA), MEMC Electronic Materials (NYSE:WFR), SuntechPower (NYSE:STP), Applied Materials, Praxair (NYSE:PX), MGP Ingredients (NASDAQ:MGPI), and Air Products & Chemicals (NYSE:APD).

Furthermore, many of the companies that were nominated are actually held by this fund, including Evergreen Solar, Energy Conversion Devices, Ballard Power, and Zoltek.

The Foolish conclusion
Although the WilderHill ETF is down about 12.5% since the community singled it out for investment, David Gardner remains confident in its potential. And the Rule Breakers community is actively following alternative energy companies as they stand out. (In addition to the stock recommended in the April 2006 issue, another company highlighted during the exercise was recommended in the June 2006 issue.)

The power of community is particularly important in growth investing, which requires novel methods to analyze the potential of stocks in nascent sectors. Why? Because great growth stocks often cannot be analyzed using traditional metrics like P/Es or DCFs. Instead, we look for companies on the verge of breakthroughs that will reshape their industries -- and the more eyes we have looking out for the next great growth stocks, the stronger our likelihood of success.

The Rule Breakers community is more than 10,000 strong, representing a vibrant collection of ideas, interested in not only alternative energy but also nanotechnology, biotech, robotics, and other exciting new technologies. Join the crowd free for 30 days -- and you, too, can be part of community-powered ideas in growth investing.

This article was originally published on July 28, 2006. It has been updated.

Alyce Lomax does not own shares of any of the companies mentioned. Suntech Power is also a Motley Fool Rule Breakers pick, while is a Stock Advisor recommendation. The Motley Fool has a disclosure policy.