Who all has one of these? It's called Character Map or Charmap. It is a grid with all the different characters you can type on Windows (I don't know if there's an alternative in other OSs, though I assume there is). If you click on one of the characters in the grid, it tells you in the lower-right corner how to type the character. Usually have Num Lock on, hold Alt, and key in numbers on the number pad.
So, does anyone not have one of these?