In his latest entry to the Synutx blog, Ammar Ibrahim talks about an advanced chaching technique - block randomization.

I'm currenlty working on a site where I want to improve performance of dynamic pages. One of the greatest techniques to do is to cache dynamic content and serve the generated output (HTML). It's not as easy as we all want it to be when you have all sorts of weird blocks on the page: User login area, random content, ..etc

As I had a very pleasent experience with eZ components last week, I decided to take a look at the components, but then i remembered it works on PHP5. This project is on PHP4, I had to look for an alternative and decided to use PEAR::Cache_Lite.

He gives a visual example of what he's working towards and includes some sample code (using Cache_Lite) to create the blocks of content for his site. It took a few tries to get right, but apparently, third time's the charm.