Drupal has many modules available for displaying Lightbox-type content. Unfortunately for Drupal 7, there is only a few. Here's some of them reviewed.
What is a Lightbox?
Current version: 7.x-3.0-beta5
Colorbox is a lightweight customizable lightbox plugin for jQuery 1.3 and 1.4. This module allows for integration of Colorbox into Drupal. Images, iframed or inline content etc. can be displayed in a overlay above the current page.
Current version: 7.x-1.0-beta4
YoxView is a free Lightbox-type media and image viewer jQuery plugin. It's easy to use and feature-rich.
Current version: 7.x-1.2