CSS element hover effect

There are quite a number of ways to create this effect.

in css html effects at 04.05.07

Pure CSS Tooltips

Tooltips with CSS only

in javascript tutoriales css html at 04.05.07

Tables Vs Lists - css-discuss

in css lists navigation tables html at 02.05.07

A List Apart: Articles: CSS Design: Taming Lists

CSS Design: taming (X)HTML lists, creating great-looking navigational menus and other visual effects. Working with lists :)

in CSS lists navigation style structure presentation at 02.05.07