DOMEdit
Simple javascript to allow immediate editing of DOM.
After running DOMEdit.js hover your mouse over an element. Once it is selected you can press:
k: to 'cut/yank' the element and add it to a stack
u: to pop an element from the stack and append it inside of the selected element
y: to pop an element from the stack and place it after the selected element
o: to pop an element from the stack and replace the selected element
Requires JQuery