How does User Experience and Agile interact?

The whole idea of 'User Experience' has always meant a relatively long process to describe the requirements and validate them, meaning there didn't seem to be a good fit in an Agile team. Alas, I find myself re-thinking my ideas when confronted with new information.

Here is an article that describes one project's efforts to integrate UX tasks into an agile project.

http://johnnyholland.org/2010/10/21/beyond-staggered-sprints-how-theladders-com-integrated-ux-into-agile/