I've been looking for new batteries for Janne's digital camera. We're getting tired of buying expensive Duracells. The cheap batteries go dead almost immediately.
After having read the Wikipedia articles on batteries and discovering that lithium-ion AA-compatible batteries do not appear to exist (update: I later found some on batteribyen.dk, but unfortunately not rechargeable), I was going to buy Sanyo 2700 mAh rechargeable batteries from batteribyen.dk. The shop owner recommended Sanyo Eneloop, however. They are supposed to be able to keep their energy for longer. But they are only rated for 2000 mAh...
But then I found this page (which in turn references this test, I also found another big test). Apparently some cameras are very picky with the voltage they get from the battery, turning off at the point most batteries deliver the bulk of their energy at.
But not the Eneloops. So I'm going to be buying a set of those with a charger.