And the 18650 is about to be produced on a massive scale in the Tesla Gigafactory.
Personally I've recently switched from conventional AA rechargeable NiMH batteries to low self-discharge NiMH batteries (branded Eneloop) and am very impressed - things like my keyboard and mouse were needing to be recharged every 2 days or so and now I can go 2 weeks or more.
If you have enough light in the room a solar keyboard is also pretty awesome, I had one for the longest time. Kept it until I accidentally broke the keys cleaning it. Keyboard selection is very much based on taste though, so I assume you probably saw one and didn't like it.
I've got a big pile of Eneloop batteries; I've even pretty much swapped out the old generation for the new low-discharge generation by sheer use and wearing out the old set. It takes a lot but it can be done.
And I can't help but notice that if you take this at face value and this really does multiply alkaline battery life by 8, the economics still roughly work out as a tie with existing NiMH batteries in terms of cost... and if the tech fails to do 8x, which I tend to agree is quite likely for the vast bulk of uses, it still leans in favor of NiMH for most things.
Agreed on the greatness of Eneloop: I've used these in my Bluetooth keyboard and mouse for a few years now, and they also do a very neat USB-powered charger.
(Other brands do low self-discharge MiMH batteries too -- e.g. Duracell -- but I've had much less luck with those).
Personally I've recently switched from conventional AA rechargeable NiMH batteries to low self-discharge NiMH batteries (branded Eneloop) and am very impressed - things like my keyboard and mouse were needing to be recharged every 2 days or so and now I can go 2 weeks or more.