What visual aid should I use for my informative speech?

I have to give a speech for my college math course on a famous mathematician named Leonhard Euler. Here is a little about him: Euler was partially blind in his 20s and become completely blind later on in his life. He was from Switzerland and some say he was the inspiration for the popular sudoku puzzles today (although a Japanese man named them "sudoku"). I cannot think of a good visual aid for my speech. I want something creative and different, but nothing cheesy or stupid. I was thinking of handing everyone in class a sudoku puzzle to solve at the end of my speech, but this is kind of dumb because there are sudoku puzzles right in our math books. Help!? Thanks so much!