The concept of casual screen sharing is that multiple users can cast screen images from their personal hand-held devices on to a large shared local screen. It has applications in personal and business domains where documents or images need to be discussed in a shared environment. The ‘casual’ qualifier implies that the overheads of this sharing should be minimal. Implementation of casual screen sharing poses two general problems: sending content from multiple devices with minimal or no authentication/authorisation, and displaying this content on the larger screen. This paper proposes a solution and describes the development of a prototype, CasualShare.