eLyXer is a python app that converts a LyX file to a nicely formatted HTML page. The files I tested worked a treat, so very excited.
To install this on a Mac, first get Macports if you don’t already have it. Then, from the terminal, run:
sudo port install ImageMagick sudo easy_install elyxer
If you’re lucky that’ll work. If you run into a problem with ImageMagick, you probably need to install Java Development Package for MacOS X (don’t ask, some weird dependency of a dependency). It’s worth the effort.