Damian delivered a session on AJAX in Geneva. This is a good introduction of AJAX.
The screencast is one hour long and 25GB, and available here: http://damianblog.com/2007/02/25/ajax-screencast/
Wow 25GB??? How many days did it take to film it ;-)
My typo in the original blog :-) 25MB actually!
It's a typo. It is 25 MB.