Many organizations no longer assign their employees permanent desks. Instead they follow the hoteling method. This involves workers being assigned a workspace whenever they check in at the office. A particularly useful practice when a business has many employees who are regularly out in the field or on the road. Needless to say there is software which helps assign seating and records who worked where and when. Condeco has an add-in for Outlook that helps employees select an available workstation. Collecting data from these systems can be an important aspect of electronic discovery. The data from such systems will make it possible to pinpoint which groups of attorneys shared a space where they were likely to confer and observe each others activities.
Conference room scheduling tools such as RoomTrack, RoomWizard, or SharePoint equivalents can let you know exactly when groups of people met in person - and perhaps which topics they focused on.