Also, I started using the YUI toolkit, and it appears it may be later, rather than sooner, for the prototype installment.

A couple quick comments:

(1) I’m pretty sure tha display: table, table-row, etc don’t work under IE6.

(2) It is possible to have div’s as two “columns” side-by-side. You do this with float. The floatorial is great introduction to floats:

http://css.maxdesign.com.au/floatutorial/

However, you will inevitable run into trouble with clearing floats in a cross-browser fashion. The best technique I’ve found for doing this is here:

http://www.positioniseverything.net/easyclearing.html

There are can still be issues under some browsers with float-based layout inside of a float-based layout under a couple browsers.

The sad thing is, that even in this modern CSS world, the only portable way to make table-like layouts, is still with tags…