Share 'Creating customizable panel layout'

Hi all, I am completely new to flex, and I'm just beginning to discover its many capabilities. I'm wondering how easy or difficult it would be to create an application in which panels or widgets could be rearranged by the user, such as on iGoogle or many other customizable sites. I think the arrangement of panels would be saved to a cookie, which I also don't know how to do with flex. I know ...