The nature of the blogs is such that the newest posts are on top, and few older ones are underneath. Whatever is older then that goes to the jedi archives. The reader who happens to stumble on the blog, will probably check the few last items, and not very likely dig through the archives to see if there is something which he will be interested in.
This form of presentation is certainly good for things like fashion, politics, technology, and news in general, because in those areas, the old news is really less worthy then new one, and being such, it is ok to put them into archives. Because of this, such sites as memeorandum, blogniscient or megite work.
Tagging and putting the posts in categories, and providing search field are common practices, and those do help prolonging the life of the post, but it might be argued that if the post need to be searched for by the person who stumbles on the site, the metaphor of the post being on life-support is more suitable.
One possible solution is to provide some kind of maps, which would provide visual hints about the relations between different topics.
Because of this, I added semantic network (kind of), a graph which gives overview and links to the pages connected to inquiry into meanings of the terms, and put it directly accessible from the “Recommended entry pages” list of links in the sidebar.
Note 1:A bad thing is though that it doesn’t work as planned :( . WordPress deletes tags from the posts, so the links directly from the graph don’t work.