This is a long shot, but I'm interested in using AA cells for things that normally use Li-Ion batteries. As you can see I'm a cyclist, not a hiker, so the considerations are very different. (I want to go touring with my MP3 player, headphone amp, UMPC and camera. And my bike light uses Li-Ion too.)

I hike with several li rechargeables. I recharge them from AA's that run a USB charger.

If your gadgets charge from USB you can do it too. Follow this link.

http://www.ladyada.net/make/mintyboost/

In my case, I use a light weight flexible solar panel on my back pack that recharges NIMH AA's that I then use in the USB charger to charge my phone, MP3 player and Camera.

Thanks Keith, that's a handy setup. But if I'm going to carry AAs I'd prefer to eliminate the Li-On batteries altogether. And only one of my toes is rechargeable via USB.