I don't walk often; if I did it wouldn't be an issue. Also, I'm skeptical increased speed would help. If I'm not doing anything else while listening, my attention drifts away, which I don't think would be assisted by increasing the speed. The lack of related physical action is the main issue; I find it enormously difficult to not fidget away any focus I had.
Why do you want to use audiobooks? The usual reason is so that you can learn or enjoy a good story while you are doing other stuff. If that's the case for you, then do that stuff and your lack of physical motion is solved. If you have another reason, have you considered taking up walking just to enjoy your audiobooks and for exercise? How about knitting? Woodcarving? Keeping ones body occupied is not an unexplored problem.
As for speeding up, I was a lot more sceptic that it would help me concentrate on videos before I tried it.
This is an extension of a comment I made that I can't find and also a request for examples. It seems plausible that, when giving advice, many people optimize for deepness or punchiness of the advice rather than for actual practical value. There may be good reasons to do this - e.g. advice that sounds deep or punchy might be more likely to be listened to - but as a corollary, there could be valuable advice that people generally don't give because it doesn't sound deep or punchy. Let's call this boring advice.
An example that's been discussed on LW several times is "make checklists." Checklists are great. We should totally make checklists. But "make checklists" is not a deep or punchy thing to say. Other examples include "google things" and "exercise."
I would like people to use this thread to post other examples of boring advice. If you can, provide evidence and/or a plausible argument that your boring advice actually is useful, but I would prefer that you err on the side of boring but not necessarily useful in the name of more thoroughly searching a plausibly under-searched part of advicespace.
Upvotes on advice posted in this thread should be based on your estimate of the usefulness of the advice; in particular, please do not vote up advice just because it sounds deep or punchy.