Bad Handwriting, Undeliverable Mail, and Improvements in OCR
The question of what happens to your mail when the address is illegible offers a view on how much OCR technology has improved.
The Terrible Price of Free: On E-reading Jane Austen via Google's Ebooks
The new Google Ebooks have made a mess of many popular classics in the public domain.
reCAPTCHA: Workforce of Accuracy
Software that protects against spam can also help digitize old text.