If you would like the navigation along the top, simply move the ul.nav to the top of the page and recreate the styling.
By nature, the background color on any div will only show for the length of the content. If you'd like a dividing line instead of a color, place a border on the side of the .content div (but only if it will always contain more content).
This .footer contains the declaration position:relative; to give Internet Explorer 6 hasLayout for the .footer and cause it to clear correctly. If you're not required to support IE6, you may remove it.