Duracell's latest NiMH rechargeable batteries have two neat features. One, they hold power for up to 365 days without use, and two, they come pre-charged, so you won't have to juice them up before plopping them into your camera. The first is great so your batteries are always ready for use even if you haven't touched them for a while, and the second is great so your batteries are ready for use when leaving the store. Too bad these are $12.99 for a four-pack. [PRNewswire via Coolest Gadgets]
I don't have very many items that use regular batteries these days, but I've been using Sanyo's Enerloops for my Wii for a good seven or eight months with no complaints.
Long lives, fast charging, minimal loss over time. I should add that my mom tried some (not the same individual ones) in a digital camera and they drained ridiculously fast. Not sure if she had bad batteries or if they just don't hold up in high-drain situations.