Secrets of the self-made billionaires

What's the difference between a millionaire and a billionaire? And what does it take to bag those three extra, all-important zeros?

Put such questions to America's wealthiest entrepreneurs--luckily, we can--and you will get a wide array of thoughtful, intriguing and even playful responses.

In pictures:
Secrets of the self-made
The difference between seven and 10 zeros

As to the divide between seven and 10 digits, billionaire Leon Charney--former adviser to US President Jimmy Carter and now the host of the The Charney Report, a TV news-talk show--summed it thusly: "reverence for humility, isolation, envy, superficial compliments and lost relatives coming out of the woodwork." Tequila and hair-product magnate Paul DeJoria on the distinction: "absolutely nothing."

In the accompanying slide shows, self-made members of the 2008 Forbes 400 list offer an exclusive peek into their thoughts, quirks, strategies and more--compelling reading when you consider that this bunch has launched hundreds of companies, employed hundreds of thousands of people and bagged (wait for it) a combined $1.08 trillion!

In pictures:
Is charitable giving effective philanthropy
How to spot a liar

We coaxed these titans into revealing whom they turn to for advice (a handful said "No one"); where most of their deals go down (restaurants were popular spots, though motorcycles and ski lifts made the cut); what questions they ask in an interview (casino mogul Phil Ruffin's favorite interrogation: "How much are you going to sue me for?"); and what watering hole deserves "best bar on the planet" status (a question that manufacturing giant Michael Heisley felt too inadequate to answer, as he's never drunk a drop).

They even told us whom they would most rather be for an evening: Michael Jordan or James Bond. (Nine said Bond; six, MJ; and two said "neither.") Condominium developer Jorge Perez's justification for choosing 007: "I prefer women over basketball." Tom Secunda of Bloomberg fame picked Bond, too, but admitted that he'd "rather be Derek Jeter or even better Eric Clapton." (Don't worry, Mike: Pharma king Patrick Soon-Shiong wants to be you "for a week.")

In pictures:
What's the coolest number in your cell phone?
How would a billionaire invest $100,000 today?

Six of the top 10 spots on The Forbes 400 belong to entrepreneurs, as opposed to well-paid corporate soldiers or the silver-spoon set. The combined net worth of those self-made billionaires in the top 10 is $192 billion, 67% of the pie. And of the entire list, 271 (68%) are self-made, up from 270 last year. Average net worth of all self-made members: $4 billion.

In video: Billionaire secrets

While their conquests run the gamut from oil and fertilizer to real estate and leveraged buyouts, these billionaire-entrepreneurs also have a few things in common, according to our 20-question survey. Valuable commodities include pets and sleep. And most claim that, despite their rocket rides to wealth, they have done a decent job of keeping long-standing relationships intact.

Other answers were all over the map, such as their thoughts on the estate tax; which historical event they'd like a front-row seat to; and even how much cash they keep in their wallets (Charney's answer: none.) When asked what will touch off the next economic crisis, Secunda replied, "Let's get out of this crisis before we hit the next one." Point taken.

The surveys are filled with perspective, but perhaps 58-year-old financial whiz and cricket enthusiast Allen Stanford, whose eponymous firm manages a whopping $51 billion in assets, best captured what it takes to make a bundle on one's own steam. Asked if he preferred "the chase or the kill" he replied: "Any entrepreneur will tell you they are equal."

Clarity of mission and love of the journey: No wonder the guy's worth $2.2 billion.