Visual interfaces may facilitate human to computer interaction as well as computer to human communication. In this paper, we introduce Garnet, a novel visual interface for interaction between humans and Digital Libraries. Garnet provides a visual workspace in which the user can structure and organize documents of interest. This structure is then used to organize and filter further documents which may be of interest, such as search results. Spatial hypertexts are introduced as a framework for creating DL interfaces, and Garnet is compared to existing DL and Spatial Hypertext systems.