ProfileMonitor uses the SkinTemplateSetupPageCss hook.
This
seems to exist from 1.6.0 upwards. The extension is in Subversion.
Rob Church
I need to output css and javascript, and this one only outputs css. It
did however lead me in the right direction. "BeforePageDisplay" in
SkinTemplate.php is available in 1.7+ and the comments say it is
specifically there to allow extensions to add css and javascript. I'll
update mediawiki.org's hooks list so this is easier for the next person.
Thanks for the help everyone!
V/r,
Ryan Lane