2. Add a <div></div> with a class of the current pages node number (again prefixed by "node") around each page.
Now I'm awake again, I've realised that it would be better to add an id attribute to the <body> tag, rather than adding a separate <div>. Something like:
<body id="www-perlmonks-org 1234">
Where 1234 is the node number of the page in question.
This kind of thing has become known as a CSS signature and allows you to do funky things with user-style sheets. See this css-discuss thread for more info.
