Element.extend an Element in Prototype
Here's a quick way to add all the Element methods to a DOM element using Prototype 1.5 (I believe the RC is right around the corner if not already here).
var div = document.createElement('div'); Element.extend(div);
That's it. Then you can do things like
div.hide(). Well, you still need to append the DIV to the document but you get the idea.