/** Requires Firebug **/

var Performance = {
    timers: {},
    start: function(tag) {
        this.timers[tag] = { start: new Date().getTime() };
    },
    stop: function(tag) {
        this.timers[tag].end = new Date().getTime();
        console.info(tag + " took " + (this.timers[tag].end - this.timers[tag].start) + " miliseconds.");
    }
};