Via Greater Greater Washington: Animated history of the T:We have our animated history of Metrorail. Vanshnookenraggen has created a similar animation showing Boston's T growing (and sometimes shrinking) over time.
[Of course, if you are interested in this stuff, see what we have done over here.]
Krista Nordback @ Vehicle for a Small Planet: Guest post: Adjusting for variation in bike counts.
NYTimes: Biking and Sexual Health in Women.