On August 23, 2006, Don Badaczewski and Matt Green spent all day and night in the New York City subway system, in an attempt to break a speed record-- how fast could they pass through the 468 stations in the entire system? The last record was set in 1998 at just over 25 hours.

I met up with them for a few hours to find out what happens on such a marathon journey, and why they wanted to do it.