Harnessing the power of students when they are using the elliptical and putting this electricity back into the grid. Shows users their calorie burning efforts are also electricity generating.

Also, Oregon State University and University of Oregon have these and have competitions between them to see which college can generate the most power in a week long competition.

http://oregonstate.edu/recsports/sweat-power-green-power

Definitely a cool attraction that makes you want to work out.