Maybe the sun is the key for future energy... Well, now is tomorrow, and there are already new ideas about this cheap alternative energy:

http://www.instructables.com/id/DIY-Solar-Boombox/

http://www.flickr.com/photos/47642593@N00/...57600117133010/

http://yosemiteoutside.com/m/Blogs/02EA4A6...E4B24C3AAB.html

http://www.instructables.com/id/Solar-Battery-Charging/

http://www.instructables.com/id/Small-Solar-Panel/

http://www.solio.com/charger/index.htm

The guys at Sony have already in 1987 a solar model from one of there famous Walkmans :

http://www.walkmancentral.com/products/wm-f107