I'm still convinced that the skills of librarians are paramount to the success of utilising web 2.0. I'm starting also to think that individual and social psychology have a role too (I KNEW there was a point to studying Humanities...)
This video from Mike Wesch (via Stephen Dale) illustrates the power of searching, removing the need for a pre-organised filing system, but with the underlying need for effective tagging.
Folksonomies are powerful, in that they are driven by the searcher, it's filing by a democracy, but searching is anarchic...anyone can use the term they think of to look for whatever they are thinking of.
Understanding individual differences, different spelling, interprettation, ways of thinking and being, can all help us to understand what language different people might use to find something. Searching is only as effective as the tagging behind it. The more people rely on searching to find information, the greater the need to understand we're all very different beasts. Information management is becoming as much about how information can be made accessible, as it is about the information itself. If you want your information to be discovered, used and appreciated, you need to put yourself in the shoes of the people you want to find it.