Just wondering if there is a module or some way in general to do the following:
When hovering on a page link show the content of that page as a tooltip or some kind of small dropdown window.
Beauty Tips is a drupal module and a jQuery plugin that will allow you to display content tooltip style via hover, click or a range of other events.
It provides an API for adding custom beautytips as well as some built-in features. Admins can enable rollover balloon-help style tooltips for text fields within forms. It also supplies hover tips for Drupal help links and advanced help links.
Most importantly, it allows developers to add their own custom beautytips popups to their site without having to delve into jQuery.
You can use this module and fetch the data which do you want to display in tool tip.