I have recently been learning how to design using CSS. It's requiring a whole change in the way I think about designing sites, but it is very rewarding. Here is a great site about column layouts using CSS.

There are numerous advantages to making the switch to CSS, the main ones for me being: leaner code (faster to load), more accessible sites and the sites are much more search engine friendly - i have a feeling this last point will become more important as time goes on.