CSSColStuff

body {
	font-family: Verdana, Geneva, Arial, Helvetica, sans-serif;
	font-size: 76%;
	/* 76% was the smallest value the author found that worked. */
}

h1 {
	font-size: 1.5em;
}

h2 {
	font-size: 1.25em;
}

p {
	line-height: 1.25em;
}

More ways of doing 3 column layouts

This one looks good. From http://www.pixy.cz/blogg/clanky/css-3col-layout/:

body {
		margin:0; padding:0;
		font:11pt/1.5 sans-serif;
		}

	#header {
		margin:0; padding:0;
		background:yellow;
		}

	#main1 {
		margin:0; padding:0;
		background:yellow url("red.gif") top left repeat-y;
		}
	#main2 {
		margin:0; padding:0;
		background:url("blue.gif") top right repeat-y;
		}
	#left {
		float:left;
		width:150px;
		margin:0; padding:0;
		background:url("corner.gif") top right no-repeat;
		font-size:80%;
		}
	#right {
		float:right;
		width:150px;
		margin:0; padding:0;
		background:url("corner.gif") top right no-repeat;
		font-size:80%;
		}
	#middle {
		margin:0 150px;
		background:yellow;
		font-size:80%;
		}
	.column-in {
		margin:0; padding:0.5em 1em;
		}
	.cleaner {
		clear:both;
		height:1px;
		font-size:1px;
		border:none;
		margin:0; padding:0;
		background:transparent;
		}
		
	h1,h2,h3,h4 { margin: 0.2em 0 }
	p { margin: 0.5em 0 }
	a { color:black }
	
	.copy { text-align:center; font-size:80% }

A more complicated version is at http://www.redmelon.net/tstme/3cols2/noborder.htm