I'll never forget the day I heard those two words.

It was Christmas 1999. I was on the phone with an old pal. That summer, he'd tipped me to a local scientist who was boasting that he could crack the human genome. There was an IPO. I bought in and forgot it.

What the heck is going on here?
Sure, biotech was on fire. Amgen (NASDAQ:AMGN) had recently doubled. Lesser-known drug plays MedImmune and ImClone -- since gobbled up by AstraZeneca (NYSE:AZN) and Eli Lilly (NYSE:LLY), respectively -- had done even better. But this was something else.

By New Year's, my genome stock was doubling every week. As it turns out, some Fool named David Gardner had bought it for his online "Rule Breaker" portfolio. In December 1999, I had no idea what those two words meant, but I had to find out. This guy was moving the market.

You may have heard that Rule Breaker investing is back. But I warn you, it's probably not what you think. It's certainly not what I thought it was when I heard those two words on the phone from my parents' kitchen in Canton, Ohio.

For one thing, it's not all tech
Yes, there was some technology in the original Rule Breaker portfolio. But as it turns out, it's not so much disruptive technologies David Gardner and his "Rule Breaker" disciples were after as disruptive businesses. I'll explain.

Southwest Airlines (NYSE:LUV) was a Rule Breaker. Yet founder Herb Kelleher didn't invent the airline. He broke the mold with a no-frills, low-cost structure and by giving a darn about his customers. Of course, you could pay similar compliments to JetBlue (NASDAQ:JBLU). Both were Rule Breakers at one point.

Dell (NASDAQ:DELL) didn't invent the computer, either. It just redefined the way computers are sold -- there's the difference. In fact, David Gardner argues that low-tech Starbucks is the consummate Rule Breaker. Who better than Starbucks, he asks, sensed a need, met it, branded it, and then spread it like wildfire from coast to coast?

Hardly high tech, right? But you know what really made Starbucks a Rule Breaker in 1998? There was no precursor and no second fiddle. If you bought Starbucks along with David in 1998, congratulations: You're a Rule Breaker, too.

So just what makes a Rule Breaker investor?
To find out, I caught up with David Gardner himself and asked him. His reply might surprise you: "It's an investor who can embrace the contrary nature of paying up for great growth stocks." This is an important point.

As David points out, great growth companies rarely look "cheap," at least when measured by traditional valuation metrics. So you have to pay up. That takes guts, but Rule Breakers can be worth the gamble. Should you take David's word for it? I would.

When David shuttered his real-money Rule Breaker portfolio, he'd managed a 20.1% annualized return. That was in mid-2003, after the bear market. Compare that with 9.1% for the S&P 500 and 7.3% for the Nasdaq over the same period. That kind of performance over 10 years made a legend of Peter Lynch, and rightfully so.

This stuff is not for everyone
Growth investing can get hairy. I learned that myself when the genome stocks blew up in 2000, and more recently when David and his team recommended another biotech, Encysive Pharmaceuticals, and closed it at a loss.

Then again, Vertex Pharmaceuticals (NASDAQ:VRTX) is up 190% since David's team told us about it, while the team closed out its Myriad Genetics (NASDAQ:MYGN) position for a 250% gain.

The trick, of course, is spotting opportunities like these and having the guts to buy when you do. It certainly helps to get your information (and support) from someone you can trust -- someone who does the legwork. In other words, not from some wahoo on the phone.

So why not go straight to the source?
If you have an eye for innovation and think high-growth investing may be for you, here's an easy way to find out. Just take a 30-day free trial to David Gardner's Motley Fool Rule Breakers newsletter. You can check out the complete service and see exactly what David's analysts are digging up now.

I can't promise you'll get rich quick. But I can promise you won't be hounded to subscribe. And that you'll learn something new and get some great stock ideas you wouldn't have heard about otherwise -- including the team's top ultimate growth stocks for new money right now. If you want to learn more about taking a no-risk free trial, click here.

This article was originally published on Dec. 16, 2004. It has been updated.

Paul Elliott  does not own shares of any companies mentioned. Starbucks is a Motley Fool Stock Advisor recommendation. Starbucks and Dell are Inside Value recommendations. Vertex is a Rule Breakers selection. Eli Lilly is a former Income Investor pick. You can view all the Rule Breakers picks with your free trial. The Motley Fool owns shares of Starbucks and has a disclosure policy.