Guardian Technologies, a bulletproof-vest company he runs in his spare time, went public in June at $5.10 for a unit of a share and a warrant.

And North's business partner in Guardian Technologies, a bulletproof-vest company, is Joseph Fernandez, a former C.I.A. station chief who figured in the Iran-contra affair.

"Pulling out liquid containers is a fairly easy step," said Steven V. Lancaster, vice president of Guardian Technologies, of Herndon, Va., which makes detection equipment.

Guardian Technologies already makes software that analyzes the images produced by X-ray machines.

If Guardian Technology pick it up it goes to an audience of 1.6m. If Stephen Fry notices it, it's global.

Charles Arthur: Guardian Technology is switching its bookmarking system over from the ex-Yahoo Delicious service (now owned by the YouTube founders) to Pinboard, a paid-for service.

You don't need to sign up; you can watch the flow of messages from a particular user at their username (eg Guardian Technology's, which is at twitter.com/guardiantech).

This is Guardian Technology.

This might be the worst article that has ever appeared on Guardian Technology.

The word first appeared in these pages - and now Guardian Technology has its own podcast too: Tech Weekly.