Ajax - a mythical Greek hero or a new web app. model

There's been quite a few posts about xmlHttpRequest (Ajax) recently with Google making it seem cool now they've stuck it in a few apps (Orkut, Gmail, Google Groups, Google Suggest, and Google Maps)If you think you havent read enough about it then check out Adaptive Path. They have got another/new post about Ajax, including a good diagram showing how it sits in the web application model.