it seems they have developed a skipping rope which will allow you to charge batteries. it uses the kinetic energy to charge it. but i think its a total waste.
http://www.environmentteam.com/2010/07/26/modified-skipping-rope-to-recharge-batteries-using-kinetic-energy/
designers have designed a new wing that would help aircraft's to reduce the fuel consumption by nearly 6 percent.its good that more time and effort is been invested to improve fuel efficiency.
http://www.environmentteam.com/2010/07/14/wing-tip-device-to-improve-aircraft-fuel-economy-by-6-percent/