aside scroller.js

gistfile1.js

jQuery(document).ready(function() {
	var triggers_in_viewport = [];
	checkTriggers();
	$(window).scroll(function(event) {
		checkTriggers();
	});

	$('aside h3 a').click(function(event) {
		showAside($(this).attr('href'));
	});

	function showAside (aside_name) {
		$('aside ul li div').hide();
		$('a[href="'+aside_name+'"]').parent().parent().find('div').show();
	}	
	
	function checkTriggers () {
		triggers_in_viewport = $("a.aside_trigger:in-viewport");
		showAside('#'+$(triggers_in_viewport[0]).attr('name'));
	}
});

This will need the viewport jquery plugin.

Download the one from here : https://github.com/NV/jquery_viewport - that's what I tested it with.