I have a Bachelor's degree in printing ("Graphic Communication") and one of the classes I took was called "Design with Type." I learned all sorts of fascinating minutia about fonts. One of our assignments was creating a one sheet with a poem or some other text along with an image behind it. Besides the layout challenge, we had to use a system where the kerning was turned off and we had to manually code ALL of the kerning.
So far, I haven't had the patience to take the test GD linked to to see if I retained any of those skills.
Another mostly useless factoid I learnt was that in Postscript (and most proper vector-based typesetting protocols), the details of each character vary ever so slightly depending on the point size; this was demonstrated by outputting the same character (same font obviously) in a 6 point and a 72 point size, then blowing up the 6 point character to the same visual size as the 72 point character to display them side-by-side. When comparing, you would see where the stroke might vary, the transition of a crossbar was more filled in on one, etc.
Another assignment was programming in raw Postscript coding. While searching for a visual illustration of the font size difference, I ran across the image below. I remember creating an image exactly like the one on the left side of this image. EXACTLY!
