I started playing with YUI while it was still in version 1, and its API was much different from what it looks like now. Among the toys I'd made was a bookmarklet to add drag and drop to any website. I used it on our internal sites until YUI was made publicly available.
A couple of years ago, I published instructions for adding drag and drop to any website, but that still needed a little technical know-how on the user's part.
So, to remedy all that, and to bring us up to date with YUI 2.6.0, I've rewritten the bookmarklet, and hosted it on yui.bluesmoon.info (no, there's nothing else there). It's far simpler, than the earlier version, and without further ado, here it is: Make Draggable.
Simply drag that link to your bookmarks toolbar, and you're ready to use it.
Now, if you click on the bookmark (in your bookmarks toolbar) when you visit a website, most sections of the page should become draggable. Enjoy yourself rearranging your favourite pages.
Let me know if it doesn't work for you, and let me know of additional features that you'd like to see. Yes, remembering your past state would be cool, but is probably not something I want to do right now.