document.write() vs. DOM manipulation

gistfile1.txt

document.write("<div id='foo'></div>");

// OR

var div = document.createElement("div");
div.id = "foo";
document.body.appendChild(div);

// keep in mind, body.appendChild will put this <div> at the end of the body, whereas document.write() will put it wherever it's called (probably in the middle of an element.
// SO....

<p id="bar"></p>
<script>document.write("<div id='foo'></div>");</script>

// is roughly the same as:

<p id="bar"></p>
<script>
var bar = document.getElementById("bar");
var div = document.createElement("div");
div.id = "foo";
bar.parentNode.insertAfter(div, bar);
</script>

// AND...

document.write("<script src='...'></script>");

// is roughly the same as:

var script = document.createElement("script");
script.src = "...";
document.head.appendChild(script);