People are skeptical when I say economic efficiency means environmental efficiency. They often point out externalities as a counter argument, though if you defend property and individual rights, this problem can be mediated: pollute my land, and I sue you. Outside of the tort system, here's a way you, as an individual and as a consumer, can both save a lot of money and save the environment.
Don't throw away your batteries when they're dead! Any student of chemistry knows that a battery is a reversible chemical reaction. The truth is, many alkaline batteries can be recharged. Now the reason why I use the qualifier most is that some batteries are purposely designed to malfunction when you recharge them, to get you to buy more of course.
What I use is a discontinued Rayovak Recharger, which is a scaled down version of this one. I don't know why they stopped making these, but perhaps they did when people found out they could recharge any alkaline battery, as opposed to just rayovak brand rechargeables. Recently, Rayovak launched a new line of rechargeables, but I have not tested these out to see if these still work.
Ideally, any automatic recharger works (the kind that shut themselves off when they detect a full charge), but be careful testing. You can even do it yourself if you're adventurous. One thing I must point out though is that the chemicals inside the battery can irritate your skin, so if you see any sign of leakage, remove the battery with a thick paper towel and wash your hands. You'll notice a distinctive sour odor when batteries burst, which is another way of telling if they've malfunctioned. If the leakage got onto the charger or electronics, you can either wipe it down immediately or wait until it dries and dust it off. Also, if the battery stays warm a while after you've charged it, that means that the battery shorted and can no longer be used. Also, most batteries have some kind of expiration date on them, and this is a good rule of thumb as to your success in recharging the battery.
Ideally you should be able to recharge the batteries as often as you want until the battery can no longer be recharged. If you want, you can use a permanent marker and add a tally mark each time you recharge your batteries.
Good luck, have fun, and remember, safety first!