In his current work with a project staring the Zend Framework, Nick Halstead has figured out a way to create a tag cloud that can be loaded quickly with the help of the Zend_Cache component.

Zend_Cache is a caching mechanism that either lets you cache chunks of output or chunks of data. Both concepts are easy to implement within your code and given time they become second nature to use. And because they are simple to implement you find yourself using them anywhere and everywhere.

In his example, he grabs treed category data and dumps it (formatted) into a Zend_Cache object. He also mentions what he calls a "touch of genius on the part of the Zend Framework team" - the ability to tag the cache and make it easy to reference.
Finally, it's back out to the front end, an interface to the cached object that pushes the data back out as a series of formatted links pointing to content associated with the chosen tag.


Nick Halstead's Blog: Making a TAG Cloud out of Zend_Cache - Read More...