The best place I've found for these batteries, at least US, is
www.thomasdistributing.com
A set of 4 AAs that will outlast standard alkalines by about half is $8, the fancy 2300 mAh that go twice as long as standard alkalines are $14. The charger is $30 but they have a fancy international one is $45 WITH 4 batteries and a mandatory battery holder. I say mandatory because you would not want these batteries to short out on change in your pocket.
The down side to these batteries is that they don't hold a charge very long, and so if you have a set around for a month you really have to charge them (for an hour) before using. But they are really ideal for digital cams that use AAs, where you can charge up a couple sets for a week and have them at the ready.