I love me some Nyan Cat! ... And I wanted a quick way to make this --> https://dl.dropboxusercontent.com/u/6213850/WebGL/nyanCat/nyan.html into screensaver of sorts to run fullscreen in a browser window with some dynamic camera motion, so wrote a little javascript snippet to run in console to achieve just that. Tweak to your hearts consent...

gistfile1.txt

setInterval(function() {
	var w = document.querySelector("body").offsetWidth;
	var h = document.querySelector("body").offsetHeight;
	var c = {x: w/2, y: h/2};

	var tolerance = (w < h ? w/8 : h/8);

	var dx = c.x + (Math.random() * tolerance) * (Math.random() > 0.5 ? 1 : -1);
	var dy = c.y + (Math.random() * tolerance) * (Math.random() > 0.5 ? 1 : -1);

	var event = new MouseEvent("mousemove");
	event.initMouseEvent("mousemove", true, true, window, 0, 0, 0,dx, dy, false, false, false, false, 0, null);
	document.dispatchEvent(event);
}, 3000);