Many viruses are harmless in their regular hosts (and therefore difficult or impossible to detect) but devastating if they switch to a new one.

ECONOMIST: Pigged out

Scientists have used chromophores for decades to detect chemicals, but, until Fido, they weren't sensitive enough to detect trace explosives because each molecule of TNT vapor would switch off just a single chromophore, with the result that faint wisps of evil chemicals caused no visible change in luminosity.

FORBES

Keeping with the contextual phone skills, Samsung's Smart Stay feature makes the device detect (through the front-facing camera) whether a face is looking at it in order to switch the display on or off.

ENGADGET: Samsung Galaxy S III preview: hands-on with the next Android superphone (video)