My son brought a reading book home from school yesterday, called My Friend Mr Leakey, which turned out to be by the eminent scientist J.B.S. Haldane. I didn't know he had written any books for children, but I did know he had written accessible books for grown-ups as well as professional scientific papers. One of his most widely-read works is an essay called On Being The Right Size.
According to myth, Thomas Watson of IBM once predicted a global market of perhaps five or six computers. (There is no documentary evidence of this prediction.) Greg Papadopoulos, CTO of Sun Microsystems, now makes a similar prediction: The World Needs Only Five Computers. (See also interview with Greg by Stephen Shankland.)
We're talking pretty massive computers here. Think Amazon, eBay, Google, Microsoft, Wikipedia and Yahoo, each with thousands of servers linked together into massive server farms. In order to make sense of Greg's prediction, we have to regard the Google grid as a single computer. And there is a plausible scenario in which all the computing power in the world is increasingly consolidated into a handful of massive global grids.
And of course Sun Microsystems has long been associated with the slogan "The Network is the Computer", coined by John Gage in 1984.
So what is the right size for a computer?
Wikipedia: John Gage, J.B.S. Haldane, Thomas Watson sr