Overlib Mod is a simple addition to Erik Bosrups overLIB v4.21, which handles all of the init items for you, plus parses out tags to make the script easier to implement.

It is limited in it's capabilities, since I really only use two standard types of tool-tip, but expanding on them wouldn't be too hard. You can grab the script from here or check out the specific changes here.

Examples:
Titled

<a href="#" rel="tooltip" data="Title|Content">Titled</a>

<a href="#" rel="tooltip" data="|Content">Untitled</a>

An additonal item that I find handy are seperate config files for the overLIB settings. I think it's easier to handle configuration in external files like this, just like templating in any other form of web media (CSS, Smarty, etc.)

Here are some configs I've made, they're quite small and simple to change to your needs. Really they're just some variable declarations. Click the links to preview them.

» grey.js - A nice gery theme.
» vc.js - A blue theme like VelvetCache.org's design.
» purple.js - Some purple's based off of php.net
» orangered.js - Orange-ish and red-ish colors, a nice mix.
» uno.js - UNO Mav Red and grey.