Consider that it is completely legal to make an audio tape of a CD for personal use (and for personal use only). (If I'm wrong here, someone please point me to a reference. I haven't been able to google up firm proof either way, just this from the EFF.) I.e. for people to listen to their cds on tape while driving or exercising. So cross-media copying can be fair use.

I'd argue that this is exactly the same thing as what we're talking about - scanning a book that you did pay for, to have a mobile copy. (The example where you download this copy from a warez site is much more shaky though.)

But that's just my opinion; for all I know, legally things might be different for books (vs. audio and video tape).

Law aside, I also don't think it is morally wrong to make personal (and only personal) electronic copies of a book that you did pay for. (And again, the deal with the warez site is a different matter.) If it was a library book that you just checked out, that would be ethically wrong, and I'm pretty sure it's legally wrong as well.

-- Frag.