[OS X TeX] [TeXShop] character O et 0

[Sylvain CHAMBON]

howdy !

is it possible to have in the editor window of texshop the character 0  
(zero) crossed out in order to save me from confusing with the  
character O ?

i actually use Lucida Sans Typewriter which is pretty cool but 0 and O  
seem to be the same character. i don't find a suitable font for  
solving this problem...

excuse my english ;-) and thanks for answers.

sylvain