The oil market is especially sensitive even to a hint of expansion or contraction in supply.

The history of the Internet is, in part, a series of opportunities missed: the major record labels let Apple take over the digital-music business; Blockbuster refused to buy Netflix for a mere fifty million dollars; Excite turned down the chance to acquire Google for less than a million dollars.

What an economy really wants, after all, is not more investment per se but better investment. It wants capital to flow to companies that will create value - not in the form of a rising stock price but in the form of more goods for less cost, more jobs, and rising wages - by enhancing productivity.

Self-dealing, essentially, occurs when managers run companies to line their own pockets instead of those of the companies' owners. It's been a perennial problem in American capitalism and became a real dilemma when America moved toward a model in which corporations would be run by professional managers who had only small ownership stakes.

The Xbox 360 is the best game console ever designed. It's fast and powerful - games look as good on the 360 as on high-end PCs that cost six times as much. It's easy to navigate and has lots of useful secondary features - the ability to play digital video, stream MP3s, and so on.

Under the right circumstances, groups are remarkably smart - smarter even sometimes than the smartest people in them.

Technological innovation has dramatically lowered the cost of computing, making it possible for large numbers of consumers to own powerful new technologies at reasonably low prices.