The last <table>-based website that I did was tomswebplaces.com, which I believe was in 2003. A lot has changed since, both on the web and the way I write HTML. But today I remembered <table> usage once again; that is, using <table> for layout and design, rather than tabular data.
The task at hand: to align text vertically in a div. At first quite trivial — div inside div, first position:relative, second position:absolute — until it comes to text wrapping. When text wraps to the next line, there's more white space above the box than below. I could not believe that there isn't a native solution for this. Few google queries revealed long forgotten display:table-cell, combined with vertical-align:middle achieves desired behavior. It works perfectly on all standard compliant browsers; however, IE6 and IE7 that do not support display:table-cell.
Below is the way I solved IE6/IE7 problem via adding extra wrapper <span /> around the block that is to be vertically aligned. This wrapper is used to imitate vertical alignment in these two non-compliant browsers, while proper layout is display in all, dare I say, normal browsers; it isn't perfect, but it works.
<html>
<head>
<style>
div {
border:3px dotted #ccc;
height:140px;
width:50%;
display:table-cell;
vertical-align:middle;
}
</style>
<!--[if IE 7]>
<style>
span {margin-top:-1%;}
</style>
<![endif]-->
<!--[if lt IE 7]>
<style>
span {margin-top:0;}
</style>
<![endif]-->
<!--[if IE]>
<!--[if !(IE 8)]>
<style>
div {
position:relative;
}
span {
height:140px;
top:40px;
display:inline;
position:absolute;
padding-top:3%;
}
</style>
<![endif]-->
<![endif]-->
</head>
<body>
<div>
<span>
Long text that we want to vertically align in the middle in a div. Another sentense.
<span>
</div>
</body>
</html>
In a couple of weeks, you will see how I utilized this method in production environment on slashdot user pages. 
04/01/2009 update: finally I am able to reveal where I used this method: http://slashdot.org/~f1vlad/achievements, all achievements boxes are utilizing this.