Here is a follow-on to my remarks upthread about experimenting with taking audio books on a tiny MP3 player with an external speaker. I found that it didn't work as well as I wished and I am back to regular old paperbacks in the 4 oz to 6 oz range.

The problem was that if my attention strayed for more than an instant, I would miss some words, and I never felt right about these lacunae. Rewinding was possible, but a pain, compared to just glancing a bit higher on the page.

I would guess that an MP3 player would work much better for listening to radio-type material, where a brief lapse of attention is less critical than with literature.