Originally Posted by
rasadesign 
It's not that tabled sites don't use CSS. The distinction is that layout and style tends to be shared between CSS and tables in a tabled design. Tableless design uses tables when appropriate, but Structure and Style (layout) is separated. Structure in the HTML, Style in the style sheet.
Clarifying Further:
As an e-Commerce, designer, there's an SEO reason to use tableless design, but it seems to be little understood factor that isn't being picked up in the posts to this thread.
The ability to write semantically correct markup in the 'logical' contextual order that presents keyword strings within an readable hierarchy is what makes tableless design useful for e-Commerce. It's why we rewrote osCommerce into a
tableless CSS osCommerce application for our clients.
The fact that we can put important content and navigation directly in line with TITLE, H1, H2 and P up at the top of the source code is what makes the page seem more relevant for that particular keyword string:
PAGE TITLE: Blue Widgets
H1: Blue Widgets
H2: Very Blue Widget description
P: "Our bluer than blue widgets are the best because they are made from..."
We can go further and create a DIV with an ID of header, then have that above information contained with "display:none" in the CSS with a background image consisting of the logo. Viola! Google sees keyword-rich text and readers see your $2,000 beautiful, graphical logo.
Right under that, another H2 followed by the main page content. Following that, the keyword-rich text links that lead to pages with matching TITLE tags. After that, all the rest of the less important content, 'about us' page links, etc.
That order in an e-commerce site pops the site up past tabled designs, all else (such as link popularity) being equal.
Why? Because, to Google and other readers, the hierarchy is clear. In a tabled design, the logical order of the content and its importance is not always so clear and rarely linear.
But, before we can let the whole debate between tables verses tableless, here's a couple of reality checks:
http://joeclark.org/book/sashay/seri...Chapter10.html
http://css-discuss.incutio.com/?page=TablesVsDivs 
