Writing in Slate, Microsoft's online magazine, Mr Myhrvold explains that the main problem with usage-based charging for electronic information is that it is an artificial distortion of the underlying economics.

ECONOMIST: So many ways to pay online

Appliance usage may be a main effect variable in epidemiologic studies of health impacts of electromagnetic fields.

FORBES: The Truth About Risks, Benefits of the Smart Grid

"All the routes that were reduced have been checked and found to be under the degree of usage and priority that we would require for a main priority road, " he said.

BBC: Gritter

The witness said she had looked at mobile phones usage an hour before and one hour after the bomb exploded in the main street.

BBC: Omagh bomb scene