BaVa,
<body>
<div></div>
<script>
function typeText(elem, text) {
var i = 0;
var stop = false;
var si = setInterval(function() {
if(text.length === i) clearInterval(si);
else {
if(elem.textContent !== undefined)
elem.textContent += text[i];
else if(elem.innerText !== undefined)
elem.innerText += text[i];
}
i++;
}, 408);
}
var div = document.getElementsByTagName("div")[0];
typeText(div, "ololo ololo lololo lolo");
</script>
</body>
или так
<body>
<div></div>
<script>
function typeText(elem, text) {
var i = 0;
var TextNode = document.createTextNode('');
elem.appendChild(TextNode);
var si = setInterval(function() {
if(text.length === i) clearInterval(si);
else {
TextNode.data += text[i]
}
i++;
}, 408);
}
var div = document.getElementsByTagName("div")[0];
typeText(div, "ololo ololo lololo lolo");
</script>
</body>