Good cross-browser method for tooltips?

Giganews Newsgroups
Subject: Good cross-browser method for tooltips?
Posted by:  usen… (Morten)
Date: 1 Dec 2004

Hi. I'd like to be able to make tooltips for some "span" elements. So
I'd do like:
<dic class="toolblock">Stuff<span class="tooltip">Something about
"Stuff"</span></div> and then use the below stylesheet:

div.toolblock span.tooltip {

div.toolblock:hover span.tooltip {
  display: block;
  position: absolute;
  top: 200px; left: 0; width: 125px;
  padding: 5px; margin: 10px; z-index: 100;
  background: #ffff80;
  border: 1px solid;

I would like a more robust way that allows relative placement in
respect to the "span". What's the recommended approach?