There was a bit of an outcry when the Google Books program started but I have to say that as I would not have been able to get to most of the libraries around the world where these texts are stored it is a huge, HUGE boon to the researcher to be able to access the scans of the texts in a searchable form.
Some early material I accessed dated back to the 16th century - pretty good being able to access these works from my own home.
Some of the more recent items were just as interesting.
The clipping below is from a Quaker Newspaper known as the "Friends Intelligencer" and has some great insights into how people of the day used coffee.
Friends' Intelligencer By Friends Intelligencer Association, Friends Intelligencer Association
Now I haven't tried the yolk of an egg instead of cream, and while first thing in the morning that might turn my stomach, I will give it a go one morning after breakfast. I guess it is good to keep in mind that the people mentioned in the article were not drinking espresso but a brewed coffee into which the yolk would be stirred - it would add body I guess. . .