AJAX is great for reducing page flicker when posting back to the same page (for instance, updating a listbox or a textbox), but a lot of a web-site navigation involves clicking around to different pages.
DHTML behaviour has been around a good few years allowing page developers to have page transitions (such as wipe, chequerboard etc.) when the page loads and unloads. None of these transitions were that great and a certain amount of flicker was still present.
I’ve seen a few sites recently that have a nice fade transition that is much smoother than DHTML behaviours. I’ve just discovered from this blog, how it’s done.