CSS Refresh (as seen @ http://cssrefresh.frebsite.nl/)

cssrefresh.js

function refreshLink(link) {
	var instance = this;

	var pageDomain = window.location.href.match(/\/\/([^\/]+)/);
	var linkDomain = link.href.match(/\/\/([^\/]+)/);

	if (!pageDomain || !linkDomain || pageDomain[1] != linkDomain[1]) {
		return instance;
	}

	instance.link = link;
	instance.href = link.href;
	instance.refresh = 200;
	instance.timestamp = +new Date;

	var request = window.ActiveXObject ? new ActiveXObject( 'Microsoft.XMLHTTP' ) : new XMLHttpRequest();

	var timeout = function () {
		request.open('HEAD', instance.href, true);
		request.send(null);
	};

	request.onreadystatechange = function (e) {
		if (request.readyState == 4) {
			var timestamp = +new Date((request.getAllResponseHeaders().match(/Last-Modified:([^\n]+)/) || ['', ''])[1]);

			if (instance.timestamp < timestamp) {
				instance.href = instance.href.replace(/#.+/, '') + '#' + timestamp;

				instance.link.href = instance.href;

				instance.timestamp = timestamp;
			}

			setTimeout(timeout, instance.refresh);
		}
	};

	setTimeout(timeout, instance.refresh);

	return instance;
}

function refreshLinks() {
	var instance = this;

	instance.refresh = 200;

	var timeout = function () {
		for (var a = document.getElementsByTagName('link'), i = 0, l = a.length, e; i < l; ++i) {
			e = a[i];

			if (!e['data-refresh']) {
				e['data-refresh'] = new refreshLink(e);
			}
		}

		setTimeout(timeout, instance.refresh);
	};

	setTimeout(timeout, instance.refresh);

	return instance;
}

Usage: new refreshLinks()