Flip! It - A jQuery Plugin
If jQuery were a beautiful woman I would marry it.
The options this jQuery plugin has are very interesting as well. Designers and developers can define the content of the flipping box (works with HTML, text or a jQuery object), the direction they want that content to flip, the background starting and ending color as well as the speed.
Here are a few recent posts related to jQuery from Website Magazine:
Blow Users Minds With Three jQuery Plugins
jQuery Design: Pan & Cross Fade Animations