Someone asked about this on the MT forums, and I really liked how the answer turned out, so I thought I'd add it over here.
Some weblogs have a specific set of categories and would like to divide up the index page in columns to help segragate the posts. One such blog is BlogCritics. Other news-format blogs could be easily enhanced this way too.
This code will create the classes for the stylesheet and then the html to display them by using MTArchiveList tags. The stylesheet is adapted from Glish's example.
<html>
<head>
<title>Categorized Columns.</title>
<style><!–
body {font-size: 13px; font-family: verdana;}
<MTArchiveList archive_type="Category">
#<$MTArchiveCategory$> {
width:23%; change this depending on how many categories you have
float:left;
padding:10px;
}
</MTArchiveList>
–></style>
</head>
<body>
<MTArchiveList archive_type="Category">
<div id="<$MTArchiveCategory$>">
<$MTArchiveTitle>
<MTEntries lastn="2"> change this to how many posts you want to show for each category
<b><$MTEntryDate$><br></b>
<$MTEntryBody$>
</MTEntries></div>
</MTArchiveList>
</body>
</html>
You can see how this looks on my lovesongs (my music blog) test page. I'd recommend not using this if you have more than 5 categories, as it will leave pretty skinny columns!