Has anyone used http://www.gpsvisualizer.com? Pretty cool. There is a draw function that lets you map a route and export the resulting file, and an import function that lets you import the file and display the elevation profile. Having just got back from Blue Knob, I tried it out on the upper part of Extrovert (to the intersection with rt 66).  I came up with a grade of 75-80%, around 37 degrees.

Should also mention - when I try it on the whole length of Extrovert (top of the run to the dogleg right) I get 56% or 29 degrees. This is consistent with what I have seen elsewhere.