Tim Bray notes much discussion about taxonomies for organizing one's blog entries, akin to those categories you see on the left of this blog. My big concern is that as content fills this blog, and I want to do some reorganization, I can't, because that would break too many URIs unless I then commit to doing HTTP rewrites to keep it all straight. Another option would be to move from using the taxonomy as part of the permanent URI of the entry, and instead use the date.