Have you perhaps considered a book scanner? You can then sell books and for an additional fee turn the book into a DRM free PDF the user can read electronically. You don't sell digital copies online just give the reader the book they bought in store. This way the reader can read the book physically or by a tablet.
I have a bookcase full of textbooks of $60-$120 a piece that I'd love to have digitized for like 10-20 bucks per kindle-readable book.
Rebuying it on Amazon usually costs the same ridiculously high price or higher, and the books aren't always prepared nicely either.
I think this is actually a great business idea. Imagine you could just send in, or drop off books that you then receive in DRM free glorious PDF or other nice e-book formats.
There is a company that does this. They were very successful in Japan and opened an office in San Jose a few years ago - http://1dollarscan.com - be sure to read the FAQ. They can also do OCR on the book content which makes it searchable and possible to do copy/paste. As far as I can tell what they do is the normal graphical scan of a page, and then underlay that with text. When you select over the page it picks up the text, but when you read you see the graphical original.
Note that they destroy the books in the process of scanning them (spine is cut off) and then they dispose of the books to avoid copyright and similar issues.
Modern scanners will produce a 'searchable PDF' comprised of two layers - OCRed text below, scanned image on top. So you get the search and copy ability of OCRed text, but not the loss of presentation and formatting that comes with using OCR alone. As with any OCR, you do get occasional mis-transcribed words.
Google Books doesn't let you download an entire DRM free book to your Kindle, does it?
