Plots your political position on a dual-axis grid taking into account both economic and social values: a more sophisticated system than the old standard of left/right, liberal/conservative. And it does a rather good job, too, at least in figuring out where I stand - I came out just where I ought to be, way down in the lower left corner.
Economic Left/Right: -9.38
Social Libertarian/Authoritarian: -8.21
The authors analyse a number of well-known political figures as well, and indicate where those individuals would likely fall on the grid. I feel just fine being in the same quadrant as Gandhi, Mandela, and the Dalai Lama.
Found out about this from mishaslair
Take the test at http://www.politicalcompass.org/