README

Drop in replace functions for setTimeout() & setInterval() that 
make use of requestAnimationFrame() for performance where available
http://www.joelambert.co.uk

Copyright 2011, Joe Lambert.
Free to use under the MIT license.
http://www.opensource.org/licenses/mit-license.php

requestAnimFrame.js

// http://paulirish.com/2011/requestanimationframe-for-smart-animating/
// http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating
 
// requestAnimationFrame polyfill by Erik Möller. fixes from Paul Irish and Tino Zijdel
 
// MIT license
 
(function() {
var lastTime = 0;
var vendors = ['ms', 'moz', 'webkit', 'o'];
for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame']
|| window[vendors[x]+'CancelRequestAnimationFrame'];
}
if (!window.requestAnimationFrame)
window.requestAnimationFrame = function(callback, element) {
var currTime = new Date().getTime();
var timeToCall = Math.max(0, 16 - (currTime - lastTime));
var id = window.setTimeout(function() { callback(currTime + timeToCall); },
timeToCall);
lastTime = currTime + timeToCall;
return id;
};
if (!window.cancelAnimationFrame)
window.cancelAnimationFrame = function(id) {
clearTimeout(id);
};
}());

requestInterval.js

/**
 * Behaves the same as setInterval except uses requestAnimationFrame() where possible for better performance
 * @param {function} fn The callback function
 * @param {int} delay The delay in milliseconds
 */
window.requestInterval = function(fn, delay, args) {
	if( !window.requestAnimationFrame       && 
		!window.webkitRequestAnimationFrame && 
		!(window.mozRequestAnimationFrame && window.mozCancelRequestAnimationFrame) && // Firefox 5 ships without cancel support
		!window.oRequestAnimationFrame      && 
		!window.msRequestAnimationFrame)
			return window.setInterval(fn, delay);
			
	var start = new Date().getTime(),
		handle = new Object();
		
	function loop() {
		handle.value = requestAnimFrame(loop);
		var current = new Date().getTime(),
			delta = current - start;
			
		if(delta >= delay) {			
			fn.call(args);
			start = new Date().getTime();
		}		
	};
	
	handle.value = requestAnimFrame(loop);
	return handle;
}

/**
 * Behaves the same as clearInterval except uses cancelRequestAnimationFrame() where possible for better performance
 * @param {int|object} fn The callback function
 */
    window.clearRequestInterval = function(handle) {
    window.cancelAnimationFrame ? window.cancelAnimationFrame(handle.value) :
    window.webkitCancelAnimationFrame ? window.webkitCancelAnimationFrame(handle.value) :
    window.webkitCancelRequestAnimationFrame ? window.webkitCancelRequestAnimationFrame(handle.value) : /* Support for legacy API */
    window.mozCancelRequestAnimationFrame ? window.mozCancelRequestAnimationFrame(handle.value) :
    window.oCancelRequestAnimationFrame	? window.oCancelRequestAnimationFrame(handle.value) :
    window.msCancelRequestAnimationFrame ? window.msCancelRequestAnimationFrame(handle.value) :
    clearInterval(handle);
};

requestTimeout.js

/**
 * Behaves the same as setTimeout except uses requestAnimationFrame() where possible for better performance
 * @param {function} fn The callback function
 * @param {int} delay The delay in milliseconds
 */

window.requestTimeout = function(fn, delay, args) {
	if( !window.requestAnimationFrame      	&& 
		!window.webkitRequestAnimationFrame && 
		!(window.mozRequestAnimationFrame && window.mozCancelRequestAnimationFrame) && // Firefox 5 ships without cancel support
		!window.oRequestAnimationFrame      && 
		!window.msRequestAnimationFrame)
			return window.setTimeout(fn, delay);
			
	var start = new Date().getTime(),
		handle = new Object();
		
	function loop(){
		var current = new Date().getTime(),
			delta = current - start;
			
		if (delta >= delay) {		
			args !== undefined ? fn.call(fn, args) : fn.call(fn);
		} else {
			handle.value = requestAnimationFrame(loop);
		} 
	};
	
	handle.value = requestAnimationFrame(loop);
	return handle;
};

/**
 * Behaves the same as clearTimeout except uses cancelRequestAnimationFrame() where possible for better performance
 * @param {int|object} fn The callback function
 */
window.clearRequestTimeout = function(handle) {
    window.cancelAnimationFrame ? window.cancelAnimationFrame(handle.value) :
    window.webkitCancelAnimationFrame ? window.webkitCancelAnimationFrame(handle.value) :
    window.webkitCancelRequestAnimationFrame ? window.webkitCancelRequestAnimationFrame(handle.value) : /* Support for legacy API */
    window.mozCancelRequestAnimationFrame ? window.mozCancelRequestAnimationFrame(handle.value) :
    window.oCancelRequestAnimationFrame	? window.oCancelRequestAnimationFrame(handle.value) :
    window.msCancelRequestAnimationFrame ? window.msCancelRequestAnimationFrame(handle.value) :
    clearTimeout(handle);
};

This version is modified to allow requestTimeout to pass on an argument. It also call requestAnimationFrame before calling the function in request interval (not tested)

I think you need to change "requestAnimFrame" to "requestAnimationFrame" in requestInterval.js.
For those who find this later, the argument syntax is:
requestTimeout(functionName, delay, functionParam)