What I'm reading is the except for lighting, which only depends on one's comfort level, the lightest is to use an iPhone for everything, and bring enough weight in battery packs to keep it charged for your propective TBH (time between hotels). Can you really read books on an iPhone? Kindle of course is fine for that and goes 30 hours if one reads evenings with an LED headlamp. Hardly ultralight, though.

I brought a Kindle dictionary, but it was a real PITA. Wished I'd had some sort of translation software. Is there an app for iPhone or similar?