One common design problem is how to display a large amount of content on a page and still make it easily accessible. Often times, a table of contents is used at the top with links within the same page to sections below. This gets pretty unwieldy if you have a lot of content, and splitting it up into multiple pages can be annoying and hard to navigate.
An easy and elegant alternative is to use a dropdown list with content panels made of individual divs. The dropdown acts as the table of contents, and each time a selection is made, only that panel is displayed.
Example:
With a little bit of jQuery and CSS, it’s very simple to create this kind of ui.