Sanyo eneloop is rewriting the meaning of being cost effective -

With the United States alone accounting for over 2.9 Billion throw-away batteries a year. http://www.childlikes.com/battery.htm

Rechargeable Batteries are making a come back and the eneloop dry-cell batteries are leading the way with its ability to recharge up to 1800 times, taking cost effective to a whole new level.

http://www.youtube.com/watch?v=MRx8KsnFRek&feature=player_embedded&list=PLC9DF61E0DC3F8461

Source: http://www.eneloop.info/home.html