Formerly head of Knowledge Management at the BBC, Euan Semple initiated a collaborative knowledge environment there, starting from the first interactive system of an online forum.
Concentrating not on the development of technology, but how the technology initiated communication across the organisation. he used the example of where someone had a query regarding expenses policy which got several different answers, as well as a link to the official policy. Even beyond that, it highlighted different implementations of that policy in different departments. The forum didn't create the cultural issues, but highlighted them.
He was less enamoured of traditional knowledge networks 'knowledge coffins', taxonomies which fail because they are too proscriptive. He contrasts this with blogs, which can create networks of ideas by using permalinks, and used a visualisation of the wikpedia entry on the London bombings to illustrate how wikis are the most auditable of documents.
He emphasises that the more open the system the greater the response; and that openness engenders trust. The environment has to be wholeheartedly embraced from the top down, and policies developed from the bottom up. At the BBC there were >5000 wikis.
His own attitude was one of enthusiasm - his use of tagging and RSS to interact with networks of interest. He defined his view of the semantic web as linking "Oh, that's interesting!" sites/services/nodes.
He cited tools which could be used to connect people e.g.
Plazes (similar but automatically updates with your location)
Dracos.co.uk - tracks BBC News homepage changes