The MTA's Poetry in Motion program, which features bits of poetry on the "Subtalk" posters in subway cars, has expanded its offerings to include quotes from history, philosophy, literature, and science. The Train of Thought first selections are quotes from Galileo, explaining the role of math in science and E.B. White, from his wonderful book Here is New York.
Columbia University's Graduate School of Arts and Sciences is in charge of choosing the extracts, and the MTA's Director of Marketing & Corporate Communications Alicia Martinez explained why the program was expanded, "New Yorkers have wide-ranging interests, and we felt that we could include material from a variety of other disciplines in addition to poetry to bring important, engaging, insightful quotes to our riders, and entice them to explore the author or subject further."
You can see some recent PiM poems here. One of the 2008 poems is from Grace Paley (PDF).