I was able to change my implementation to use flXHR ( http://flxhr.flensed.com/, MIT License) which is a drop-in replacement for XmlHttpRequest that uses an embedded Flash movie to talk x-domain. There are others like it, but this one seems to be the best because it is drop-in. I had to recompile Openfire to have the crossdomain.xml allow headers to be sent from Flash, but that was the only pain.
Has anyone used this or similar? The main drawbacks I've found are: - there are platforms which don't have Flash 9 (BSD, iPhone, Win Mobile) - creating requests too fast causes them to become out of order--can probably be overcome, flXHR uses a lot of timeouts - pausing from onunload still isn't working =[ Harlan
