I tried rechargeable batteries back in 2000, and have not used any since, because they sucked donkey dong through a dirty diaper. But according to all reports (many), times have changed, and the Sanyo Eneloop batteries rock on all fronts, power, speed, holding a charge, and economy. I've already ordered a bunch and a charger.
(Amazon UK link.)
By the way, I like the kooky but memorable name, and the pleasant and simple design of these batteries.
Update: I like German companies. I ordered the charger and batteries in the very early morning, and within a couple hours, before it was even light outside and before British working people have put on the kettle and washed their face, I got an email that the item had shipped!
OK, Germany is one time zone ahead. It was still before nine in the morning, and most people in most Western countries do nothing really productive that early. Well, not white-collar workers anyway. Many blue-collar workers start quite early. I know, I was one as a young man (sand-blasting). Lord, starting at seven I was sleepy in the morning!