I've had a few people ask how to setup Growl4Rails without using rails. It's pretty easy as is, although you may be a little miffed by the directory structure. Feel free to go in and munge with the source if you'd like it to be more flexible, or to update it to suit your needs. All of the path dependencies are in the CSS files.
Once all the resources are there, all you need to do is add the includes to your layout/masterpage/template:
var growl4rails_duration = 5000;
var growl4rails_max_showing = 5;
<link href="stylesheets/growl4rails/growl4rails.css" media="screen" rel="stylesheet" type="text/css">