Postmonger.js
An ultra-lightweight Javascript utility for simplified cross-domain messaging.
For docs, examples, and more see: http://kevinparkerson.github.com/postmonger/
To suggest a feature, report a bug, or general discussion: https://github.com/kevinparkerson/postmonger/issues
Special thanks to Jeremy Ashkenas and all the folks behind DocumentCloud's Backbone.js for the event system.