Thanks to H²-=NooB=- for telling me about the existant of GeSHi (
http://qbnz.com/highlighter/).
The Ulysses forums now feature GeSHi! To use this brilliant syntax highlighter, put your code in a code block with the language you're using specified, if you were using lua you'd use [ code=lua ] and [ /code ] without the spaces. There is also a pull-down menu with a list of languages you can use, and will insert the code tag for you.
Enjoy!