While last week I interviewed superstar women — former Xerox chairman and CEO Anne Mulcahy and CNN veteran Christiane Amanpour — about what they plan to do in the second half of their lives, this week is about entrepreneurs.

I’m just back from Silicon Valley, where I moderated a panel of five twenty-somethings who founded companies that could be the real deal someday.

The session, sponsored by Intelius, was hosted by the Churchill Club, a local business and technology forum, and the Kairos Society, which encourages entrepreneurialism on college campuses. More than 100 college students and elders gathered at Microsoft’s Silicon Valley offices to learn about award-winning start-ups and their creators’ best advice.

Entrepreneurs’ advice is relevant to big business more than ever, I think, since many of the best big companies — Apple , Google , Dell , FedEx , and Netflix , among them — are led or guided by founders. And some of the best companies atop the Fortune 500 — Wal-Mart and McDonald’s , for example — have bosses who say, “We need to run this like a small business.” It’s true particularly today, when long-term planning is almost impossible and agility is a necessity for success.

With that in mind, I asked the young entrepreneurs on the panel for their advice. Besides the predictable — “Follow your passion” — here’s what a few of them said:

Josh Weinstein, founder of GoodCrush and RandomDorm.com: “If you don’t have someone you trust 100%, you will be micromanaging.”

Weinstein founded GoodCrush, an online social dating service, at Princeton, where he graduated in 2009. “GoodCrush started as the CrushFinder the day before Valentine’s Day in 2007, and we got 30% of Princeton in 24 hours,” he says. “We launched GoodCrush.com this year on February 8 and we have around 14,000 users and 3,000 matches at around 20 different schools.” He calls GoodCrush “Facebook for college students,” and he himself is a sort of aspiring Mark Zuckerberg. Weinstein has already tasted success, though: He was president of Princeton’s undergrad student body. Before that, while a student at Stuyvesant in New York City, he was the 2004 U.S. High School speed chess champion.

Jason Halpern, co-founder, PowerFlower Solar. This University of Pennsylvania engineering grad (Masters and B.A.) has developed a portable solar generator for farmers and the military. His other company, Tangent Robotics, is developing mechanical parts for robotics and prosthetics. “You can do all you want in a lab,” Halpern says. “But you won’t be successful unless you build connections. They don’t teach the importance of people — of connections — in school.” He grew up on a New Jersey farm and was working in a farmers market when he happened to meet a state agriculture official, who urged him to apply for a $500,000 grant. A few weeks ago, he got the grant, giving a major boost to PowerFlower Solar’s prospects.

Ben Gulak, founder, BPG Motors. This MIT student has developed a one-wheeled, zero-emissions motorcycle. Gulak, 20, calls it the Uno. It has two side-by-side wheels  and uses gyroscopic technology to remain upright. Like a motorcycle version of a Segway. “The first real Transformer,” he says. He has raised $1 million to develop the Uno (and has produced three actual vehicles), but of course it hasn’t been easy. BPG was bleeding money, due to high-priced development talent that Gulak was funding. He dumped those folks and hired younger people. “They’ll stay all night and sleep on the couch in the office,” Gulak says, adding, “I’d rather have three cheap programmers who work 18-hour days than one great programmer.”