I want to write a browser (Chrome/FF) extension that needs to select an element on a web page. I would like it to behave like Firebug's element inspector does. You click the inspect arrow and you can then hover/highlight elements. When you click on the element you want, the element is inspected. I'm just interested in the code to allow a user to select an element - not in actually inspecting it or anything similar.

Because I'm writing an extension, it might be nice if you could provide non-jQuery/Prototype/etc.. code so I don't have to distribute that.