Way back in 1998 I had a job looking after the development environment for a tier 1 while back. One of the things I did which proved useful was put together a library of links using software from Gossamer Threads. as a first pass at Knowledge Management.
This was a pre-wiki tool which allowed you to arrange a series of links hierarchically and let users rate them. It also had a newsletter feature which I used to run the Enhyper Newletter, which was a weekly/monthly list of the links I found of note. I emailed this to about 400 people all over the world for a period of several years. These days I use del.icio.us which is pretty neat - but I still use the library occasionally to refer to articles which had seminal influence, like:
Bob Hettinga's Reading List for Financial Cryptographers - I bought most of the books and read them (yes - sad I know)
SET Grid - a comparison between SSL + Credit card and bearer cash - which is a simple but effective analysis of the advantages of bearer cash against SSL/Credit card transaction.
In Operational Research, the Maestro - Conductor of Multimedia Analysis Technologies paper taught me a lot about news analysis and multi-factor target identification.
One thing the tool taught me was that levels of hierachy are an average of 3-4 levels deep - with about 7 being the maximal. Something which is observable in some of the other KM tools I've been involved in over the years.
Anyway, there's around 1400 interesting URL's to browse - so enjoy.