You say "you-ler", I say "Oy -ler" (but only because Alex put me wise to the pronunciation). He would have to be classified under "People that I'd never heard of before, and now wish I hadn't".
Evidently as Mozart, Bach or Beethoven are to music, Euler (Oy-ler) is to math.
Daniel was using Euler's Formula today in math...but I'm guessing it was a simplified version (Is there such a think as Euler's for Dummies?) - because it was basically a series of "plug and play" math questions - all relating to figuring out shapes of polyhedrons. I don't really mind that so much as the upcoming series of lessons relating to figuring out volumes of said polyhedrons. Figuring out areas of circles wasn't too much fun, and now we get to look forward finding out volumes of various prisms and cylinders. Humph. I'm guessing the answers won't fall under "glass half full or half empty". I'm going to blame it on Euler.