Now comes word that Google is entering this market. Google has launched a mobile phone version of Google Book Search that could could eventually grow to include the 1.5 million public domain books scanned as part of their digitization project.
The books currently exist as scanned images-- these mobile versions will be text created through optical character recognition. Where the computers produce only garbled text, readers can click on the sport to retrieve that part of the scanned image.
Not only does this open up smart phones to the vast public domain resources harvested through Google's digitization project, but this also shows that OCR technology has improved to the point where Google (at least) thinks it is ready for prime time.
Scanned images are just the first phase of bringing books into the digital world. Ebooks need to exist as digital text, and human-based projects like Project Gutenberg are probably proceeding too slowly. OCR is vital to the next phase of mass-digitization. We'll soon see if Google's timing is right.