Using DIV, you can easily switch things. For example, you could make this :
Menu | Content
Content | Menu
Menu
----
Content
It's easy to change it in CSS, not in HTML. You can also provide several styles (right handed, left handed, special for little screen).
In CSS, you can also hide the menu in a special stylesheet used for printing.
Another good thing, is that your content is always in the same order in the code (the menu first, the content after) even if visually it's presented otherwise.