Swamp coolers -blowing air over a large wet surface area.

FORBES: China Braces for Escalating Power Shortages

Alternating current causes two plates to attract or repel each other, sucking air in or blowing air out like as a tiny bellows would -- one that resonates at over 100Hz.

ENGADGET: GE uses dual piezo jets to keep a Core i7 laptop cool, play a merry tune (hands-on video)

Earlier this summer an anonymous air-traffic controller filing a report to Chirp, the industry's confidential whistle-blowing agency, claimed that pilots of low-cost airlines were cutting corners to achieve flight timetables.

ECONOMIST: The price of flying on a low-cost airline

News of Mr Chavez's resignation caused hundreds of flag-waving and whistle-blowing Venezuelans to surround the city's air force base, La Carlota, in the hope of seeing Mr Chavez' departure from the country.

BBC: Venezuela's new dawn

Using powerful vehicle-mounted air blasters, soldiers can search for contact wires by blowing away leaves, sand and soil.

ECONOMIST: Anti-IED technologies

Current HVAC systems get rid of stale, germ-ridden indoor air by cooling or heating fresh outdoor air and blowing it through ventilation ducts, a process that gobbles electricity.

FORBES: Companies & Strategies