I was surprised to find that only one out of ten people in a class I recently spoke to admitted to knowing about the Internet Archive. For city directories and parish register transcriptions alone its worth knowing about, and replete with other useful resources for the genealogist.
Try it out by going to www.archive.org/details/texts and searching on a town name of your interest.
The search doesn't get into the body of the text. Do do so click on the title of the book of interest, then click on "Read Online" in the left hand column, then search from the box at the top of the right hand column.
The University of Toronto continue to add digitized books to the Internet Archive. I recently found The universal assistant and complete mechanic : containing over one million industrial facts, calculations, receipts, processes, trade secrets, rules, business forms, legal items, etc., in every occupation, from the household to the manufactory (1880). This was the world our ancestors lived in.