Although I mainly write about software in this technology blog, I’d like to include information useful for everyday life and the environment. So, here goes…
One of the ways you can save some money and the environment is by using rechargable batteries. Here is some information to get you started.

One of the drawbacks of rechargables has been the inability to maintain charge over long periods of time. This translates to unreliability. For eg. You go hunting in Alaska and want to mount your moose-head, the power-drill that you had loaded with charged batteries 6 months earlier is dead because the batteries have discharged.
In the past few years, a new low discharge battery using NiMH (Nickel-Metal Hydride) has come out, called LSD (low self discharge). This is better than the older NiMH and the oldest and most common NiCd (Nickel Cadmium). LSD batteries hold their charge over a very long time, around a year or so.

Note: There are still some places like smoke detectors, survival and emergency equipment, etc. where you should use regular batteries because they are the most reliable in terms of holding charge over real long periods of time irrespective of temperature conditions, and also have fixed voltage ratings.

LSD batteries are pretty easily available nowadays. I use Sanyo Eneloops, like these SANYO AA Eneloop 4 Pack, and most big battery manufacturers offer similar ones.

One of the keys to using LSD batteries effectively is proper charging and discharging. That means, you need to use a good charger, one that charges NiMH and provides individual control on the charging and has a discharge cycle.
I use the La Crosse Technology BC-900 AlphaPower Battery Charger. The cool thing is that it comes with spacers for using AAs in D size battery slots.

To get started, go around the house and survey your equipment and gadgets and make a list of all devices that can use rechargables and the battery size and quantity and make a single order to save on shipping and maybe get a bulk-discount. Remember to choose a charger with the required quantity capacity.

If you want to read in more detail, I found a well-written article here:

Hope this helps get you started to using rechargables.