Ok, I thought I had it nailed down, but recently while checking out the pages with firebug I noticed that the CSS isn't actually being loaded like I thought it would be.

So perhaps I'm missing this somewhere? Here's my current code-call for it.
function zenTwitterToCSS() { $css = USER_PLUGIN_FOLDER . '/zenTwitter/zenTwitter.css'; $link_css = ''; return $link_css; unset($css,$link_css); }
Edit:

Nevermind, another tired night and missed an obvious problem, the lack of use of echo on the variable.

If you want to automatically add that into the head of the page you can also use addPluginScript('...'). See the flowplayer3 plugin for an example.

Thanks for that tip acrylian! Much easier to do it that way, and one less edit that an end-user would have to do to use it. Much appreciated.