Well, this one isn't as interesting as the user graph that I made, as there aren't really well defined communities of tags that are emergent through visualization. Nonetheless, it does give some sense of the relationships that exist.
I lightly modified my last script to collect the data. An edge between tags X and Y is added when there is a user A, who follows tag X, and a user B who follows tag Y, and user A follows user B. Not as explicit of a relationship here as there is between followers and followees, so I suspect that contributes to some of the muddiness.
Anyway, enjoy. Works best in chrome. Click stop layout to plot the edges. Hover over a tag to hide all tags that are not directly connected to it.
Yea, this one wasn't as interesting as the user one. The only thing I learned is that tag communities on Hubski aren't really well defined, perhaps due to the common ones that connect everything. In order to pick out groups of related tags, one could walk through the graph and delete the most common edges that are walked upon. That's basically the idea of betweenness centrality, and the general consensus is that if you remove the edges with the highest centrality, you're left with communities. It's an approach often applied to graphs when you want to analyze communities in a larger system.