An iPod audiobook, yes, but then you will need extra batteries. Hang on. batteries are probably lighter than a book and they are multi use so maybe you are correct.
Now all I need is the iPod, the battery pack for backup batteries, the lithium batteries, once I have that then all I need is to decide which book, but it must be available at ITunes or its equivalent.
But then a trashy novel from a roadside cafe is also multi use, fire starter, TP replacer, ...
Hmmm much to think about