Most people limit their gambling to friendly Super Bowl wagers or the occasional trip to Vegas. Celebrities, of course, tend to do everything on a grander scale. Let's take a look at some famous people and the high-profile bets on which they cashed in or lost big.

1. Truman Defeats Dewey, Jimmy the Greek Defeats Vegas

Everyone remembers the "Dewey Defeats Truman" headline from the 1948 presidential election, but Harry Truman wasn't the only big winner that night. Legendary gambler Jimmy the Greek had bet $10,000 on Truman at steep 17:1 odds. His logic? His research showed that female voters weren't too keen on candidates with facial hair, which didn't bode well for the mustachioed Dewey.

2. Arnold Palmer Bets on Romance

When golfing legend Arnold Palmer met his wife, Winnie, he had a problem that a lot of young guys run into: he couldn't afford an engagement ring. He was still an amateur golfer at the time, and he was barely scraping by on his meager income. Eventually, he borrowed money from a group of pals to cover the rock.

Palmer wasn't crazy about having this sort of debt, so when the same group of buddies proposed a trip to New Jersey's Pine Valley Gold Club, he jumped on the chance to chisel away at his obligations.

When they hit the links, Palmer offered the boys this bet: he would get $100 for every stroke he finished under 70. If he played poorly on the notoriously tough course, he would shell out $100 for every stroke he finished over 80. Although he bogeyed the first hole, Palmer repeatedly used this system along with a variety of side bets to wriggle out from under $5,000 in debt in a single weekend.

3. Getting Into the White House is Tougher Than Free Throws

Last July, NBA star Shaquille O'Neal and a member of his entourage had a fiery debate about whether or not Shaq could just drop by the White House unannounced and be welcomed with open arms. After much back-and-forth, Shaq decided he'd give it a try. If he couldn't get past the gate, he would do 1,000 pushups. If he made it inside, his buddy would have to do the pushups.

Unfortunately for Shaq, even the Big Aristotle needs an appointment to see the President. When O'Neal walked up to the gate, the Secret Service politely but firmly turned him away. He later told the Washington Post's Dan Steinberg that he was working off his debt in increments of 20 to 30 pushups. (Shaq is pictured with the Lakers and President Bush in 2002.)

4. Paul Ehrlich's Population Bomb Doesn't Go Off

Even celebrity scientists have tried their hands at high profile gambling. Stanford biologist Paul Ehrlich is famous for his grim predictions concerning overpopulation; he famously predicted in 1968 that 20% of the world's population would starve to death before 1985. As you might expect, these claims were somewhat controversial. When Ehrlich commented in 1980 that he would make an even money bet that England would not exist in the year 2000, economist Julian L. Simon had heard enough. Simon decided to book an unusual bet of his own with Ehrlich.

Since Ehrlich's underlying Malthusian argument involved the depletion of natural resources, Simon made this challenge: Ehrlich could name whatever natural resource he wanted, buy $1,000 worth of it, and pick a time frame. If at the end of the time frame the commodities were worth more than the initial $1,000, Simon would pay Ehrlich the difference. If they were worth less than $1,000, Ehrlich would fork the difference over to Simon. If Ehrlich's predictions about dwindling natural resources came to pass, the prices of commodities would skyrocket and Simon would be out a lot of cash.

Ehrlich was game. He spread his $1,000 evenly among chrome, copper, nickel, tin, and tungsten and told Simon to wait 10 years. Although the world's population shot up by 800 million people in the intervening decade, the metals' prices crashed. When the bet ended in 1990, Ehrlich had to cut Simon a check for $576.07.

5. Phil Mickelson Has a Nice 2001

PGA golfer Phil Mickelson had a hot hand during 2001. Fans might remember that two longshots won titles that year: the Baltimore Ravens won the Super Bowl, and the Arizona Diamondbacks knocked off the New York Yankees in a classic World Series. Mickelson was part of betting groups that had picked both squads. Their $20,000 bet on the 28-to-1 Ravens yielded a cool $560,000, and they hit again with $20K on the 38-to-1 Diamondbacks. And to think people used to say Mickelson couldn't get a big win.

6. Ringo Says Don't Bet on a Beatles Reunion

By 1974, legions of fans were clamoring for a Beatles reunion, but Ringo Starr was having none of it. The drummer told London reporters that he had bet a thousand pounds that the Beatles wouldn't play together that year, and that he would be happy to throw a thousand quid down on the group never playing together again.

7. Hollywood Ads Add Up

In 1999, Dreamworks' Saving Private Ryan was locked in a duel with Miramax's Shakespeare in Love for the Academy Award for Best Picture, which set the stage for an unusual bet. Dreamworks honcho Jeffrey Katzenberg bet actor Warren Beatty that his rival Miramax would run more ads hyping its film than Dreamworks would. The stakes: a $10,000 donation to the charity of the winner's choice. Beatty won the wager when Dreamworks took out 165 pages of ads versus Miramax's 118, and Katzenberg paid up.

8. Computers Are No Match for Chess Master

In 1968, Scottish chess champion David Levy attended a conference on artificial intelligence and discussed the future prospects for chess-playing computers. Although Levy was optimistic about the future of chess-playing computers, he thought developing great AI would take a while. After some debate, he bet four professors 1,250 British pounds that nobody would make a computer that could beat him within the next 10 years.

Although it took a while for chess programs to pose a serious threat to him, Levy ended up winning the bet when he defeated the program Chess 4.7 in a six-game match at the 1978 deadline. The man-vs.-machine showdown was such a big deal that even Sports Illustrated covered it.

After his win, Levy put up another $1,000 as a bounty for the first chess program that could beat him in a four- or six-game match. He eventually fell in 1989 to Deep Thought, a precursor to famed chess computer Deep Blue.