Based on Google's efforts to scan books and make them full-text searchable through OCR (Optical Character Recognition) software, a complete new field in the social sciences emerged: Culturomics. In Google's Ngram Viewer it is possible to look at the usage frequency of words or phrases over several centuries.
The idea behind it is to analyze cultural trends quantitatively. Google claims to have scanned 4% of all books ever published (approx. 5.2 million), with the best results for English-written works between 1800 and 2000. It is, however, possible to create word frequencies for Chinese, French, German, Hebrew, Russian, and Spanish as well. It works really well and is a great way to look at how the language changed over time, which terms were used, or even what authors were censored during specific historical epochs. In the pictures to the left I looked at the occurrence of the term Ministry of Defense (in German: Verteidigungsministerium) and Pablo Picasso in the German collection - where you see a significant drop during the Nazi period, when Picasso was considered "degenerate art."
Due to the changes in language over time one has to be careful using it scientifically, but it is a nice way to get a first impression of cultural changes and might trigger a more rigorous research program.