Just call hijack.init(); on document.ready.

Simplified HTML5 pushState

var documentPathname = document.location.pathname,
	hijack = {
		history: $('html').hasClass('history'),
		currentLocation: documentPathname,
		firstLoad: 1,
		init: function(){
			var context = this;
			// Normal link clicks
			$('a').live('click',function(e){
				context.firstLoad = 0;
				if (e.which == 2 || e.metaKey || e.ctrlKey) { return true; } // Ensure middle, control and command clicks act normally
				var $link = $(this);
				// Handle Exceptions first
				if ($link.hasClass('paginate') || $link.attr('rel').substring(0,9) == 'shadowbox') {
					return true;
				}
				if (context.history) {
					// If you're not an external link
					if ($link.attr('href').substring(window.location.protocol.length,(window.location.host.length)+2+window.location.protocol.length) == '//'+window.location.host || $link.attr('href').substring(0,1) == '/') {
						history.pushState(null, $link.text(), $link.attr('href'));
						context.currentLocation = document.location.pathname; //update the currentLocation variable
						context.grabPage($link.attr('href'));
					} else {
						return true;
					}
				} else {
					return true;
				}
				return false;
			});
			// Back button
			window.onpopstate = function() {
				context.on_popstate();
			}
		},
		grabPage: function(url){
			// Required for Async GA
			if (window['_gaq']!=undefined) {
				var cleaned = url.replace('http://'+window.location.host,'');
				_gaq.push(['_trackPageview', cleaned]);
			}
			$("#content").before("<div class='loader'><img src='/assets/images/loading.gif' alt='loading...' /></div>");
			$(".loader").fadeIn(800);
			$("#content").slideUp(500, function(){
				$.ajax({
					type: "GET",
					url: url,
					success: function(data) {
						var title = data.match(/<title>(.*?)<\/title>/);
						$content = $(data).find('#content');
						document.title = title[1];
						$(".loader").fadeOut(300, function(){
							$(this).remove();
						});
						$('#content').attr('class', $content.attr('class')).html($content.html()).slideDown(500, function(){
							if ( document.location.hash ) {
								var top = $(document.location.hash).offset().top;
								$('body,html').animate({
									scrollTop: top
								});
							}
						});

						$(".nav .active").removeClass('active');
						var x = $content.attr('data-navhighlight');
						if (x != 'home'){
							$("#nav-" + x).addClass('active');
						}
						pageReady();
					},
					error: function(data) {
						alert('Something went wrong. Please try again.');
					}
				});
			});
		},
		on_popstate: function(){
			if (!this.firstLoad && this.currentLocation != document.location.pathname) {
				log('on popstate fired');
				this.grabPage(document.location.href);
			}
			this.currentLocation = document.location; //update the currentLocation variable
			if ( document.location.hash != "" ) {
				$('body,html').animate({
					scrollTop: $(document.location.hash).offset().top
				});
			}
		}
	};