Just wanted to share something I ran into the other day in the course of research on PCA, a very cool motivating example, sports-related.[1] On page 13, they take some NBA player stats and graph the projection of the third PC (y-axis) against the second PC (x-axis). The third PC is a negative correlation of rebounds with assists and steals. Turns out to sort players roughly by height, placing Karl Malone (6'8") and Mugsy Bogues (5'3") at opposite extremes.

1. Faloutsos et al, Quantifiable Data Mining Using Principal Component Analysis, 1997