Re: Hosting the file somewhere for auto-updates?
Jason, after reaching stable and some momentum, try to contact Google and work with them so they host CSS3 Pie on their AJAX cdn: http://code.google.com/intl/iw-IL/apis/libraries/
This' project is a bit different, but you can try
Anyway, if you can afford the hosting and if the PHP inclusion ArnoOnline offered actually works, you can host it yourself. Just use version-numbering, so nothing auto updates and introduce bugs - But we would be able to increase the version number to upgrade.