The latest issue of Portfolio -- our first anniversary issue -- focuses on the concept of brilliance. Here's an expanded version of my opening essay for the magazine. It includes a few more references to technology players than would fit in the final version.

James Hong sat in Silicon Valley back in 2000, downing a few drinks with his friend Jim Young. Talk turned to the relative hotness of a girl they knew. This gave the pair the idea for HotOrNot.com, a dating Web site that features users rating each others' looks with all the polite sensitivity of frat boys at a kegger.

Hong, who is single, now works almost solely on creating businesses that he finds either amusing or might help his personal life. "I just try to pick projects that I would do for free anyway," he says. One such business is SaveMyAss.com, a Web site that automatically sends flowers to a wife or girlfriend on pre-determined dates.

Early this year, HotOrNot was bought by Canadians for $20 million cash. For pulling this off, Hong rates as the most brilliant man I know.

Brilliance is a slippery subject. It can be relative, or temporary, or a matter of taste. Certainly some people are brilliant beyond any dispute, ever. Einstein. Mozart. Edison. Twain. But such cases are extremely rare. We're talking freakish spikes in normal genetic variation, like Spider-Man.

But what about a more common brilliance, even if that's a bit oxymoronic? Who around us today is brilliant, and what does that mean?

I asked Nathan Myhrvold, who is among the smartest people I've ever met - which is not necessarily the same as brilliant. Myhrvold has a unique perspective: He's worked closely with two of the most brilliant men of our time. In the 1990s, Myhrvold was Microsoft's chief technology officer under Bill Gates. In the early-1980s, he worked with cosmologist Stephen Hawking.

Conventional wisdom unequivocally labels Gates and Hawking as brilliant. Why? In part because Gates is the richest man in the world - which, even if achieved by complete accident, would have to be brilliant - and Hawking manages to understand the universe better than any scientist, even while locked in a body that can't move. Both are also intellectually brilliant, Myhrvold insists. "People who are brilliant can startle me with thoughts that I can't imagine having," Myhrvold says, explaining his criteria for cranial brilliance. "They come up with stunning observations so fast, and so unique to the particular conversation, they couldn't possibly have been done in advance."

Warren Buffett probably belongs to the same club, though he doesn't affect the part of an intellectual. Buffett's brilliance, says Xerox CEO Anne Mulcahy, is in "making practical sense with issues that other leaders tend to make too complex." It's the brilliance of simplicity, like the opening of Beethoven's Fifth. Or A Horse With No Name - a No. 1 hit built on, what, two notes?

People with brilliant intellects don't necessarily achieve brilliant success. For proof, look at a list of Mensa members. Mensa is a society for people who score in the top 2% of standardized IQ tests. It has about 100,000 members. Most of them, you've never heard of - which right there tells you something. Marilyn Vos Savant, a Mensa person, is listed in the Guinness Book of World Records as having the highest IQ ever. What has she accomplished? Really, little except for becoming famous for having the highest IQ ever. Actor James Woods is another Mensa member. If he's so smart, why did he choose to play the lead in the 2003 TV movie, Rudy: The Rudy Giulani Story?

Brilliance can be fickle, changing with time. Through most of the 1990s, Steve Case was brilliant. He built AOL into a business phenomenon. Then he bought Time Warner, a merger that killed a few hundred billion dollars in wealth. So since then, Case has been anything but brilliant. I've known him the whole time. He seems like exactly the same guy.

Steve Jobs used to be an exiled loser. Ousted in 1985 from a struggling Apple, Jobs started NeXT, which didn't even make a dent on the business landscape. Now he's the greatest thing since JFK. Absolutely brilliant, he is.

Brilliance sometimes hides in pockets, away from the public eye. An eccentric man named Abe Bernstein taught Shakespeare at my high school for decades, and did it so brilliantly he made thousands of hormonal teens love Hamlet. We can probably all name a brilliant teacher, coach, minister, editor or local branch manager who happily lit up their own little niche.

Perhaps, even, you've known a brilliant conversationalist. "In Melbourne in the Fifties, there was a little guy named Gordon Kirby, gay when that was a terribly difficult thing to be in a place like that, and he was a genius dinner-party conversationalist," Austrlia-born author Gavan Daws tells me. "He could pick up on anything that was said over the food and wine and turn it into a theme -- lightning fast, fancifully, always wittily, and vastly enriching to the evening. For sustained sociable brilliance I have never seen and heard anything like it."

Ah, but one question: Do the brilliant know they're brilliant? I ask Myhrvold - who, to me, is brilliant -- if he is indeed brilliant. He says no, but gives me a brilliant answer: "If you put yourself in that camp, you might be correct," he says. "But then you're also an asshole."