This animated JavaScript tooltip script is very easy to use and lightweight at only 2kb. It is tested working in IE6+, Firefox, Opera and Safari. Jacob Gube of Six Revisions has posted the script and a walk-through of the code and the logic.

A rollover image or tooltip preview based on JQuery library - tooltip-like bubble popups that appears when you roll over link or a thumbnail. Included 3 examples of using this simple script.