Well, an old one is OCR, especially handwritten OCR. I'm doing genealogy. There is SO MUCH old handwritten material that is never transcribed, and which requires special expertise to read (old and exotic handwriting styles) and interpret (place names, writing conventions, abbreviations).

It doesn't have to be perfect. It's not as if the actual data in there is perfect. It just has to be in a form where I can search it, ideally with named entities mapped.

Quality - like deciphering the writing on scrolls buried in volcanic ash in Herculaneum - gets all the attention. But what I really want is quantity - I want to be able to search through those 5000 pages of 200 year old mildly damaged cadastral records in dense handwriting. I want to relieve the army of kind retirees who currently transcribe these sorts of documents one by one based on their own needs.