I first saw it on iht.com and said ‘wow, how they (John Weir) do that?’ This was done in 2002 and I haven’t seen it elegantly executed since on any online newspaper. I’ve seen it pop-up on occasion while banking online or reserving an airline ticket. Within the past year, I’ve been seeing it more and more while using gmail, the web application inside basecamp and, most recently, flickr. What is this ‘it’ that I keep mentioning. As an emotion, I would describe ‘it’ as an online experience that generates a “that’s cool!” or “damn, that’s convenience” or “how the heck do they do that?” Not since the dawn of HTML coding when we all tweaked simple HTML and Jscript just to get the page to do what we want, have I been excited about diving back into the world of innovative web design with Asynchronous JavaScript + XML or Ajax.

Adaptive Path breaks it down with an excellent article on “Ajax : A New Approach to Web Applications.” (thanks for the link, Jose)