What are the ways to minimize page wait from external javascript callouts?

$(function(){
  // Document is ready
});

jQuery(function($) {
  // Your code using failsafe $ alias here...
});

jQuery(function($) {
   $.getScript("http://www.yourdomain.com/scripts/somescript1.js");
   $.getScript("http://www.yourdomain.com/scripts/somescript2.js");
});

<html>
    <head>
    	<title>Test Page</title>
    	<script type="text/javascript">
    		window.onload = function () {
    			alert(document.getElementsByTagName("body")[0].className);
    		};
    	</script>
	<style type="text/css">
		.testClass { color: green; background-color: red; }
	</style>
    </head>
    <body class="testClass">
    	<p>Test Content</p>
    </body>
</html>

<html>
    <head>
    	<title>Test Page</title>
    	<script type="text/javascript">
    		alert("Are you seeing a blank page underneath this alert?");
    	</script>
    	<style type="text/css">
    		.testClass { color: green; background-color: red; }
    	</style>
    </head>
    <body class="testClass">
    	<p>Test Content</p>
    </body>
</html>

if (!window.addOnLoad)
{
    window.addOnLoad = function (f) {
    	var o = window.onload;

    	window.onload = function () {
    		if (typeof o == "function") o();
    		f();
    	}
    };
}

window.addOnLoad(function () {
    alert(document.getElementsByTagName("body")[0].className);
});

dojo.addOnLoad(function () {
    alert(document.getElementsByTagName("body")[0].className);
});

$(function () {
    alert(document.getElementsByTagName("body")[0].className);
});

if (!window.addScript)
{
    window.addScript = function (src, callback) {
    	var head = document.getElementsByTagName("head")[0];
    	var script = document.createElement("script");
    	script.src = src;
    	script.type = "text/javascript";
    	head.appendChild(script);
    	if (typeof callback == "function") callback();
    };
}

window.addOnLoad(function () {
    window.addScript("example.js");
});

dojo.addOnLoad(function () {
    dojo.require("dojo.io.script");
    dojo.io.script.attach("exampleJsId", "example.js");
});

$(function () {
    $.getScript("example.js");
});