LaTeX has some handy macros that allow the insertion of diacritics and other special characters in text mode. Relevant tables from the Comprehensive LaTeX Symbol List:
These are handy since they don't require special input methods nor remembering unicode character numbers but, more importantly, mathematicians know and use them all the time. (I regularly get emails addressed "Dear Fran\c{c}ois"!) It would be nice if some useful subset of these were recognized on MathOverflow.