The negative side of all the new, exciting electronic toys is they eat batteries like there's no tomorrow. Several years ago I had a brief flirtation with rechargeable NiCad batteries. They took forever to charge, developed a memory that reduced their capacity over time, and didn't have the oomph to power a lot of things include digital cameras... That same time a brutal price war brought alkaline battery costs at places like Costco to the point where rechargeable seemed a moot point.
About a year ago I started playing with NiMH rechargeable batteries. They solved the problem with memory and oomph, but still took a long time to charge. Even a fast charger took 2-4 hours. Rayovac has solved my last complaint with a new recharging system called I-C3. A digital chip in the battery talks to a special charger to let the battery recharge in just 15 minutes. Put the battery in a regular charger, it takes the normal amount of time. Put a regular battery in the special charge, same thing-normal time. Now it's possible to charge a spare set as fast as you can drain the batteries in your camera. I've stopped using alkalines. Check them out at www.rayovac.com.