Linear navigation can be dull. Furthermore, it requires the person browsing to think like the person who organized the navigation--from distinctions between organizational models down to the structure of the hierarchy. (What, for example, on my own site, is the difference between a "category" and a "tag"? And why is "Humor" under "Poetry" but not "Technology" or "Life"?) I got to thinking about how to break down the artificial barrier between content tags and content categories, as well as how to organize concepts in a more intuitive manner than nested lists--and came up with the following navigation system for my site (requires Flash):
Basically, the navigator places a central topic in the middle, and arranges related topics (either categories or tags) around the central topic, using both proximity and text darkness to signify how often the related topics have appeared in the same articles as the central topic. The navigator displays a maximum of six related topics at a time, with left and right buttons on the side to step through additional related topics. Click on a related topic and it becomes the new central topic. Then click on the (blue, underlined) central topic to go to that category or tag page.
I have placed a miniature version of this experimental navigational system in the sidebar. It automatically detects category and tag pages in which it finds itself embedded, and displays them as the central topic. Hopefully, this will prove a useful means for visitors to browse through related topics on the site, and find new information without having to understand artificial concepts like categories and tags, or some relatively arbitrary hierarchy.