pure css

Easiest way to have pop-up "tooltips" ANYWHERE.
Procedure to do it:

• Find the Drupal folder with your theme's .info file and
  add stylesheets[all][] = mytooltip.css (under other similar lines)

• In Notepad (or any raw text editor) make the following file :

  span.tooltip span
  {
  

  display:none;
  }
  span.tooltip:hover span
  {
  display:inline;
  position:absolute;
  background:#FFFF99;
  border:1px solid silver;
  color:maroon;
  width:200px;
  margin-top:20px;
  margin-left:-5px;
  font-size:smaller;
  line-height:1em;