>>Can I actually have the same graphical borders placed & aligned without tables?<<
What *I* would do, personally (simply because it's the easiest solution, IMO - but it's by far not the *only* solution) is to create an image and set it in the "container" div. So, your container div is 700px wide - create an image that's 700px wide and as tall as your border. In the image, place one "square" (that what they look like to me!) all the way to the left. Place another one at 150px (roughly) and another all the way to your right. Then save one square all by itself as a separate file. For purposes of example, we'll call the 700px wide image "border.gif" and the single square "square.gif".
Then you'd alter the code a bit:
(I think it's "y" anyway, it might be "x" - I always get them confused! LOL)
That'll give you the graphical border down the sides of the outer container itself (not the header, though - if you want it around the header, too, then place the #header container *inside* the #container div), and also give you the separation between the sidebar and content.
Then in the code, add in a footer:
<hr class="clear" />
</div> <!-- /main -->
<!-- IE needs this comment to be here -->
</div> <!-- /container -->
And that will give you your bottom graphical border - "height" being whatever the height of the actual graphic is.