rateLimit.js

<script>
var rateLimit = (function () {
	'use strict';

	var processes = {}; 

	return function (pID, fn, rateLimit) {
		var process = processes[pID]; 

		if (!process) {
			process = processes[pID] = {stack: [], polling: false, time: null};
		}
		process.stack.push(fn); 

		if (!process.polling) {
			(function pollingCycle () {
				var nowTime = (new Date).getTime();

				if (process.stack.length == 0) {
					process.polling = false; 
					return false; 
				}

				if (!process.time || nowTime - process.time >= rateLimit) {
					process.time = nowTime; 
					process.stack[0]();
					process.stack.slice(0,1);  
				} else {
					setTimeout(pollingCycle, 100); 
				}
			})(); 
		}
	};
})(); 

var i = 0; 
while (++i < 3) {
	rateLimit('annoyingAlert', function () {
		alert("Fortunately, these annoying alerts are rate limited."); 
	}, 2000); 
}

</script>