Have you considered hosting this file at Google Code or something like that so that we can just reference it from there and that way always be calling the most recent version of PIE?

Unfortunately, there seems to be a limitation where .htc files cannot be loaded across domains. So I don't think that would be possible.

If there is a fixed location with the newest version, it might be possible to load the HTC with a PHP file (for example once a day / week to prevent heavy load on the CSS3 Pie server). Since the PHP file is local (and can communicate with external sources) this should be no problem for loading the file into the page.

Good point. I'll give it some consideration. However I'm wary of automatic updates in general; it's possible that future versions will behave differently than current versions in certain aspects (e.g. adjusting as the CSS3 specs change) or introduce bugs which would break people's sites. I don't want to be pulling the rug out from underneath people's feet, so to speak.

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.

Yeah, the google AJAX API bits would be nice, because you can link to current OR a specific release. But the cross-domain htc bits would still be problematic if true.

What I think the nut of the problem for me is that in order to upgrade PIE I have to download the zip, extract, stomp on the old file... lots of manual steps. It would be nice if current and historical versions of just the htc had permalinks so that when I get a tweet saying there's an upgrade I can just update the file via curl in a shell script, test and if all's well commit the change and update the livesite.

That could be at google ajax api's solely for the sake of preventing people from snaking all your bandwidth by deeplinking.