Another way might be to manually link relevant back-issues that relate to a given post. But there's a big problem with this manual thing. Does the author know/remember what is relevant in her own writing? And even if, does she remember to take the pain and manually link it? Blogs being a stream of thoughts and time-based, we tend to disregard what has come before. We as authors know the connections so we don't usually take the effort to explicitly point them out to readers.
chris langreiter's Wiki like Vanilla is the best manual approach I've seen yet, being a tool that makes making connections extremly easy and natural. Also the addition of the graphical visualisation (VanillaVista) can be a very usefull tool for discovery of topics.
This all reminds me of my work trying to build an 'auto assosciator' for my blog posts (search similar entries). The idea was/is to make connections between current and past posts visible. Some of which might be long past and maybe also already forgotten by the author. That 'make hidden visible' was my main concept for this feature.
(As a side note: I just re-discovered I had written about this idea some in the preperation for BlogWalk 2.0. The circle closes)
Another though would be the topical portal page approach. Category pages are almost there, but such a portal page would also add some commentary to the listing and maybe break the strict (reverse) chronological order for better understanding. BTW, I agree that a reverse chronological order is not very suitable for readers comming in late. It's perfect if you can follow a discussion enfolding, but it's 'crap' at introducing to a topic...
Maybe a combination of all three 'automatic' tools into handcrafted portal pages would be a good idea. I envision a suite of 'data visualisation' tools as 'advisors' for the author to better make sense of her own data and better arange and present it for future referrence...
Ok, I shut up now. Just ideas and no code to show here, moven on ;)
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