(OK, I am so sorry for that headline ;-) Seriously, here are some interesting ideas for taking care of your batteries.
Getting Great Battery Life: “This isn’t about how to get a lot of shots per charge. That’s easy: use your LCD as little as possible and spend as little time as possible in the menus or with the meter on. Turn the LCD review OFF while shooting. Easy.
This is how to get years of great service from expensive batteries. Some people always seem to have problems while others have them last for years.”