Telecom Computer Security Databases Handheld Devices Tech.
Obvious candidates are creatives, CEO types and trend setters.
The converse of this are information workers, whose domain is highly structured. Examples include call centre staff dealing with account queries. I do believe this is a spectrum and that people sit somewhere along the line rather than at one end or the other. In terms of change programmes it is my experience that knowledge workers require greater empowerment than information workers. Knowledge workers require tools which give them access to a broad base of knowledge to ensure effective decisions, while information workers need tools which structure work for them to ensure efficiency and quality.