Thank you all for the feedback (and for not being offended by my heavy-handed post). I hadn't considered well enough the reasons why someone might want to scan their own paper books. Improving readability and limited physical storage space are two very good ones.
By the way,
Open Library has a large collection of scanned books, many of which have not yet been published in e-book form. Participating libraries can be found
here. PDF (scanned images) and EPUB (OCR), both protected using Adobe DRM and DAISY accessible versions are available.