[tech] Ajax
I found Ajaxian.com.
The web site has many resources on Ajax.
And, I've been interested in AjaxAC: Open-source PHP framework for Ajax.
The basic idea behind AjaxAC is that you create an AjaxAC application, which in itself contains a number of action handlers and event handlers. An application in this context might mean an entire web site powered by Ajax, or it could mean a subset of a form.
CountryRegionCityJax is an attractive sample for me.