One nifty device unveiled at the Consumer Electronics Show was the Airnergy Charger, which generates electricity just by snagging WiFi signals. A demo on the showroom floor had it powering a Blackberry from 30% to full in 90 minutes. RCA says they’ll have a USB charger available summer 2010 for $40, with a battery soon to follow. Sweet idea! It remains to be soon how efficient it really is though. [OhGizmo!] [More]