Google Ngram Viewer
March 26, 2013
A friend of mine recently linked to an article that made reference to the Google Ngram Viewer. From the website:
When you enter phrases into the Google Books Ngram Viewer, it displays a graph showing how those phrases have occurred in a corpus of books (e.g., "British English", "English Fiction", "French") over the selected years.
This looks like a useful research tool.