Well, it still helps - you can OCR a book file yourself, even if you can't see; just a few clicks and then go do something more interesting. Scanning your own book is possible, but requires sitting there throughout.

Edit: http://1dollarscan.com/pricing.php says "OCR stands for Optical Character Recognition. The PDFs will contain the OCR text layer behind the images to make the text searchable and selectable." This service is labelled free so I guess you get it (or can get it) for each scan.