Batteries and Chargers:
I currently use the Panasonic BQ390A/2PK NiMH Battery and Charger but have also used the Sony Power Charger ($15 at Amazon) until it got stolen along with all my other camera gear down in Lima Peru. Another charger which is available is the Canon CBK4-200 Rechargeable Battery Charger, I've never used it, and it's a bit more expensive. All are dual voltage and very small. They plug directly into the wall without a big heavy plug. This makes them ideal for travel...get one while you still can. Both units are sold with some AA Nimh batteries as part of the deal. The Sony seems to take longer to recharge so, if time is a factor (it often is) get the Panasonic. The flip top on the Sony is nice for containing the batteries during travel, I use a rubber band on my Panasonic charger to make sure the batteries do not fall out while being moved around...The Sony has a hinged cover which does the same thing.
Buy extra 2100 mAH (or higher) batteries if possible, they pack the best power. I always have 4 extra batteries, so that I can load a fresh set in my Canon 580EX Flash when it runs down. When I get to the hotel that night I just recharge the spent ones, and I am ready to go again. I seldom run through more than on set of batteries on my Canon 580 EX flash in a single day, so having one set in the flash and another fresh set in the bag, is more than enough.
These battery chargers are dual voltage so with a plug adapter, you can use them all over the world. See my explanation of adapters, inverters and converters here
To read my review of the Maglite Rechargeable Flashlight System: perhaps the best most durable flashlight available, click here. It's no surprise that most police and rescue teams use this one.