I just learned that the UNC Gillings School of Global Public Health
actually has public "walkstations" that can be reserved by faculty,
staff, and students.  The walkstations are treadmills with
adjustable-height desks.

http://www.sph.unc.edu/weekly_news/august_27_2012_23670_13974.html#new_walkstation

I'm not sure which will happen first: treadmills in the library, or
desks in the gym.

Keith