Recently, I have been reading a number of articles touting the benefits of table-less HTML layouts, like this one at Stopdesign.
Interested in standards-based HTML design as I am, this morning I decided to research converting the Harvard International Review's website to XHTML. I had some problems with the 3-column layout (because of the use of background images), but I think most of them have been solved. The pages I have already converted (the error pages) render fine in Firefox, but have spacing problems in Internet Explorer 6. I am tempted to ignore this (as the pages are valid XHTML and CSS), but I suspect that the sixty to seventy percent of the website's viewers that use IE will not be so forgiving.
Also on my (long) list of things to do is to get this blog render as valid XHTML. This would involve cleaning up the HTML content in various old posts where I committed various XHTML sins.