The first thing I tried out was different 3-grams of "Colorless green ideas sleep furiously". Here are the results http://ngrams.googlelabs.com/graph?content=C

The first thing I tried out was different 3-grams of "Colorless green ideas sleep furiously". Here are the results http://ngrams.googlelabs.com/graph?content=Colorless+green+ideas%2Ccolorless+green+ideas%2C+green+ideas+sleep%2C+ideas+sleep+furiously%2CColorless+green+ideas+sleep+furiously&year_start=1920&year_end=2008&corpus=0&smoothing=3 http://ngrams.googlelabs.com/graph?content=Colorless+green+i... The correlation patterns and the year where the curve picks up are interesting. It would be illuminating to map the peaks.