The InfoWorld metadata explorer: Jon Udell has made an Ajax “explorer” for InfoWorld articles that lets you click on tags to alter your dataset.
Turn the “voip” tag on, and you only see items tagged with that. Turn another tag on, and you narrow the search further. Turn off the “voip” tag to loosen things up and go off in another direction. He has a screencast which explains it a lot better.
Everything on the page is clickable. The URLs, of course, lead to InfoWorld.com articles. But every other element toggles a filter. Clicking OP hides or reveals non-Opinion items; clicking Ephraim Schwartz hides or reveals non-Ephraim items; clicking macosx hides or reveals items not tagged with macosx.
It’s really just query-by-example. You start with the whole dataset, which is currently the 800 InfoWorld features, reviews, and columns that have been tagged at del.icio.us/infoworld, and you narrow or widen the scope by clicking on metadata values.
Udell, of course, is crazy about tagging. To really appreciate his passion about this and understand where he sees tagging going in the future, I highly recommend his del.cio.us screencast from a few months ago. I don’t think you’ll look at tagging the same way afterwards.