I was carrying a 5W 12V flexible rollup solar panel (google: Brunton) along with 3 sets of NIMH batteries and the respective charger. Since I hadn't needed to use it once in 4 months I ended up giving that whole kit away to a helpfull cycle shop in Almaty.
I only have a camera, and a Palm handheld computer as far as electronics go. The camera uses 4AA's(Canon S2IS), and I'm only on my second set of Lithium's so far this trip (5 months). My Palm computer can recharge off of 4AA's as well-with about 1.5-2 charges off of a set of alkilines. Supposedly the palm can recharge off of USB ports as well, but I haven't needed to try.
I didn't/don't carry wall chargers/converters. I submit that doing so is the the most cost effective & convenient option (in most parts of the world).