One way to accomplish the vertical line in a column is to give the column (or div ID) a left border or to use a background for that DIV and repeat it vertically using CSS. That's what I'm using on my blog. The gray line is just this small image
http://blog.2createawebsite.com/wp-c...es/dot-ddd.gif repeated vertically down the page. That's one way of doing it.
And yes, you can nest boxes inside one another just like tables. You would just nest the < div > tags like you would a table tag and give each < div > its own properties/attributes.