This is old, from 2008. That means that any code described is, at best, a starting point.
Additionally, the sites that the code was tied to, del.icio.us, IceRocket and Technorati, have closed down. That makes the code useless, so I've deleted any dead-end links, which is what the example code creates.
On to the description of obsolete code…
Last year (2007), many projects were all about "Web 2.0", which is a phrase I hear far too often. When they're talking about it on the evening news, you know it's already over.
A while back, I did some work with the now defunct relaXSEO.com on microformat code. Microformats are the Next Big Thing, at least for a while. To learn about them, look in Wikipedia for starters and Google Social Networking. Those two things should keep you busy for the next week or so.
One of the more popular pages on relaXSEO that I coded makes tags for Technorati, IceRocket and de.licio.us. It generates xFolk microformat html that can be copied and pasted into a blog entry to provide the tags that those services want to see. The xFolk Cloud and Tag Generator is my version of it; same code with different defaults. It also generates the code to make a moving Tag Cloud of those same tags.
It generates the code that makes something similar to this display. It was modified to remove the links because those websites no longer exist. The link is now visible, but the code did not show it.