HA!

In 2000 the company I worked for had this sort of thing at its core.  
WebHelp used to compete with Ask Jeeves, and be one of the top 10 
search engines.  At the core of the technology was asynchronous 
Javascript.  At one point a team I lead built an app using this 
technology that allowed two users on the internet to fill out a form 
together.  We had to do some evil things to get around the Javascript 
security model to get this working, but the end result was pretty neat. 
  Doing this showed me how incredibly powerful Javascript was as a 
language.  Unfortunately, it also showed me how incredibly ugly it is 
as a syntax.

4.5 years later, it's about time someone took this and ran with it!

Ben