A question from Dave Snowden on Twitter about what I thought the best semantic search tool was and my rather facetious response "the meatware" reminded me of something I am more and more convinced of. Social networks are about finding stuff. Finding documents, finding people, even finding human contact.
I have often said that the best search engine is other people's collective memory. When people ask on a forum where to find a previous answer tell them to ask the question again. Users will almost certainly remember the question being asked and will point to the previous answer. If you are lucky, and ask the question well, you may even get pointers to various answers any or all of which could be useful. If you are really lucky you will kick off new exploration of the subject and unearth new and more current information.
Twitter is making this ubiquitous access to an outboard brain more obvious to more people and there has even been talk of it replacing Google for some. The point is you can only do this if you have a high quality network of people doing the filtering and collective noticing for you. Building up these networks, and building "credit" by helping others, will become key skills and the people who invest the effort will find the better stuff faster.