Sorry mimik007, I hacked it a little bit.
Hint.css is a tooltip library in CSS that helps you add cool tooltips to any element of your page.
TipTip is a lightweight (~3.5KB minified) jQuery plugin that helps you add intelligent custom tooltips to any element of your page.
A jQuery Plugin that make it easier to make Tooltip and Image Preview for your website. It comes with 3 tricks: Simplest jQuery Tooltip, Image Preview Gallery and Links With URL Screenshot Preview.
clueTip is a powerful jQuery tooltip plugin for creating a fancy tooltip when hover over any element on your page.
tipsy is a simple jQuery Tooltip plugin for creating beautiful Facebook-Like Tooltips based on an anchor tag’s title attribute. It’s used by Twitter, Github, Slideshare and Bitbucket, amongst others.