Typewriter Effect

Tested with MooTools 1.2

Your HTML..The javascript doesn't strip spaces at the beginning & end, so you will have it delayed if there is whitespace.

<h1 id="typewriter">Hello World!</h1>

The JavaScript

window.addEvent('domready', function() {
    var index = 0;
    var ele = $('typewriter');
    var txt = ele.get('text');
    ele.set('text', '');
    var typewriter = (function() {
        ele.set('text', ele.get('text') + txt[index]);
        if(index++ == txt.length - 1) { $clear(typewriter); }
    }).periodical(100);
});

periodical(100) sets the delay between each letter being added.