In my Scientific American column this month, I pondered why it's so hard to predict the future of technology. It sometimes seems as though it's not even worth the effort; inevitably you wind up looking like an idiot.

Especially if the gist of your prediction is that something won't happen or isn't possible. You wind up with enough egg on your face to make an omelet.

If you're not convinced, have a look at these whoppers: some of the biggest muffed tech predictions of all time, and spoken by people you'd expect would know better.

* "I predict the Internet will soon go spectacularly supernova and in 1996 catastrophically collapse."—Robert Metcalfe, founder of 3Com and inventor of Ethernet, writing in a 1995 InfoWorld column

Metcalfe is well aware how silly his prediction came to look. He ate his words—literally. In 1999, addressing the Sixth International WWW Conference, Metcalfe put a copy of his infamous column into a blender, pureed it, and drank it.

* "There is practically no chance communications space satellites will be used to provide better telephone, telegraph, television or radio service inside the United States."—T.A.M. Craven, Federal Communications Commission commissioner (1961)

Needless to say, Mr. Craven is no longer the commissioner of the FCC.

* "I think there is a world market for maybe five computers."—Thomas Watson, chairman of IBM, 1943

Of course, Watson was referring to room-size mega-machines filled with vacuum tubes. But still.

* "The Americans have need of the telephone, but we do not. We have plenty of messenger boys."—Sir William Preece, chief engineer, British Post Office, 1876

How're the messenger boys working out for you, England?

* "This 'telephone' has too many shortcomings to be seriously considered as a means of communication."—Western Union internal memo, 1876.

Oops! Western Union sent its last telegram in 2006.

* "Television won't be able to hold on to any market it captures after the first six months. People will soon get tired of staring at a plywood box every night."—Darryl Zanuck, 20th Century Fox, 1946

He was right. We've moved on to aluminum and plastic.

* "Everyone's always asking me when Apple will come out with a cell phone. My answer is, 'Probably never.'"—David Pogue, The New York Times, 2006

Yeah, Okay. I'll admit it. My prediction was wrong—but my thinking was right. I knew that Steve Jobs would never tolerate the micromanagement that the carriers (Verizon, AT&T and so on) then exercised on every aspect of every phone they carried. "I cannot imagine Apple giving veto power to anyone over its software design. It just ain't gonna happen," I wrote.

What I didn't realize, of course, is that Jobs planned an end-run—a deal that Cingular ultimately accepted, which ran like this: "You let us design our phone without your input, and I'll give you a five-year exclusive." And the rest is history.

The Bill Gates Collection

Maybe the most quoted bad tech prediction of all time never really happened. It's the famous 1981 Bill Gates quote: "640K ought to be enough for anybody." Unfortunately, there's no evidence that he ever actually said that (and he emphatically denies that he did).

That doesn't let Mr. Gates off the hook, though—he's made plenty of doozies.

* World Economic Forum, 2004: "Two years from now, spam will be solved."

Today, spam accounts for over 90 percent of all e-mail sent.

* Foreword to the OS/2 Programmer's Guide, 1987: "I believe OS/2 is destined to be the most important operating system, and possibly program, of all time."

OS what?

* COMDEX keynote speech, 2002: "Within five years, I predict it will be the most popular form of PC sold in America."

"It," in this case, was the Windows Tablet PC, where you write with a stylus on the screen. Oh well.

The Apple Collection

You could make a whole Web site just dedicated to the pundits' predictions of Apple's death. You don't hear those much anymore, but for a few years the columnists and authors seemed smugly confident.

* "By the time you read this story, the quirky cult company…will end its wild ride as an independent enterprise."—Fortune, February 19, 1996

* "Apple [is] a chaotic mess without a strategic vision and certainly no future."—TIME, February 5, 1996

* "Whether they stand alone or are acquired, Apple as we know it is cooked. It's so classic. It's so sad."—A Forrester Research analyst, January 25, 1996 (quoted in The New York Times)

* "The NeXT purchase is too little too late. Apple is already dead."—Nathan Myhrvold (Microsoft's chief technology officer, June 1997)

* "Apple's erratic performance has given it the reputation on Wall Street of a stock a long-term investor would probably avoid."—Fortune, February 19, 1996

* "'The idea that they're going to go back to the past to hit a big home run…is delusional,' says Dave Winer, a software developer." –The Financial Times, July 11, 1997

* "The iMac will only sell to some of the true believers. [It's] clean, elegant, floppy-free—and doomed."—The Boston Globe, May 14, 1998

* "For all of his success, all Steve Jobs had really accomplished was a temporary pause in Apple's long-term decline."—Infinite Loop, 1996, by Michael S. Malone

* "I'd shut [Apple] down and give the money back to the shareholders."—Michael Dell, founder and CEO of Dell, Inc., 1997

Of course, most of these quotes are from the dark period when Steve Jobs was exiled from Apple. After he returned as interim CEO in September 1997 the tide of predictions trumpeting Apple's demise quieted.