The consensus among professional forecasters is that America's GDP will grow by 2% in 2012, below its underlying speed limit, and far too slow to bring the jobless rate down.

ECONOMIST: The world economy

It can also speed up the heart rate if the pace becomes too slow.

CNN: Procedure could pinpoint source of arrhythmia

Foursquare was too slow to make any strategic decisions and speed is the harbinger of success.

FORBES: Is Foursquare's Bubble About To Burst?

The way agency search is practiced now is too slow for a marketing world that runs at the speed of light, and it is too expensive for companies (and agencies) that need to prevent harmful waste.

FORBES: Connect

"We'll speed up when we have to, and we'll slow down when we can, too, " said Delta's Mr. Holtz.

WSJ: Why Airlines Are Shrinking Flight Times