Caleb Racey from Newcastle University in the UK discusses Newcastle's implementation of Grouper, an open source system for managing user groups and access control. Some key points: 1) Grouper allows Newcastle to centralize fragmented group and identity management across various systems and applications in a standardized way. 2) Their implementation is taking a phased approach, starting with simple integrations using the Grouper Shell and later adding the Grouper web interface and web services. 3) Benefits include consistency in access control, reusability of groups, and giving applications and users a coherent interface to previously incoherent identity data. Challenges include technical prerequisites and helping users understand new group concepts.