I wrote a Python script to help me visualize my tag intersections. As you can see, computing the weights are a bit kinky, but it works.

The purpose for doing this was to help me see if I was even using multiple tags for my links. As it turns out, I have about 70 intersecting nodes (tags), 20 that are isolated (which are not included in the above visualization). What is neat is that I have approximately 200 edges (intersections). The point? As predicted, I am not much of a combination tagger - instead, I am old-fashioned and use a tag to represent a folder. I would love to compare my del.icio.us usage with others. Mail me an XML of all your links and I'll run it through my script.