For an even-keeled, mild-mannered guy such as Andrew Sullivan, it's a bit surprising that his investing nose so frequently leads him to the buzziest areas of the market. From smart grids to cyber-security to the gold rush, the Fool analyst is keeping an eye on companies that are poised to capitalize on the trends that get people talking. Today, he's sharing one business he's watching, one that he feels is a good buy now, and one that he recently bought and is now priced even more attractively, albeit with a bit more risk.

The smartest grid in class
As energy prices rise and as the number of people who care about the environment inches upward, we're looking for ways to increase our energy efficiency. ESCO Technologies (NYSE: ESE) has smart grid technology that can transmit data along power lines and advanced metering technology to react to that data. Ultimately, if things go according to plan, that will allow the company to tailor the power supply to each home, saving money and energy all around.

After growth slowed to a crawl over the past two fiscal years, the company got a power boost in the most recent quarter. Revenue leapt 42% from the first quarter of 2010, and earnings per share increased from $0.02 to $0.40, crushing analyst expectations. As a result, shares jumped substantially this month, making the stock a little less appealing to Andrew at the moment but still worth watching.

Cutting through the complexity
With its wealth of knowledge and experience, SAIC (NYSE: SAI) has the task of solving complex IT and organizational problems, primarily for governmental clients. That audience makes the business fairly immune to recessions: "Governments are always going to exist and they're always going to have problems," Andrew says.

While business is strong across the organization, Andrew is most excited about the 10% of its work focused on cyber-security. "A lot of companies say they're in this area, but that's because they want to be connected with the industry buzz. SAIC is the real deal. They have the best cyber-security in the industry," he says. And that's just part of why Andrew thinks this is a good buy now.

Gold in them thar hills
Up third is Andrew's most recent purchase for his Rising Stars portfolio, Rubicon Minerals (AMEX: RBY). As he wrote:

Rubicon Minerals' past success is just the beginning. As it enters into production and the size of its large deposits is further delineated, the market will take notice. There is also plenty of upside potential from potential new finds in its large Red Lake holdings and other properties. Finally, it is a prime acquisition candidate, and buyout premiums in a rising gold market could be substantial. All those strengths make Rubicon a wonderful way to gain exposure and leverage to gold.

The stock took a hit this week on news that the British Columbia Securities Commission has ordered the company to amend its technical report. But while Andrew acknowledges that boosts the risk factor, it also presents a nice buying opportunity. "I've been watching this company for more than a year -- I could be wrong, but I don't think it's a fraud. I'm willing to take that risk," Andrew says, all but pounding the table for emphasis. So much for mild-mannered.

You can keep your eyes on all of these companies by adding them to My Watchlist, your free and customized hub for the news and numbers on the companies you care about. Just click a link below or go to to get started.

Roger Friedman doesn't own shares of any of the companies mentioned above, but he'll be watching them. SAIC is a Motley Fool Inside Value pick. The Fool owns shares of SAIC and Rubicon Minerals. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.