Preface -- Cluster Observations of the Cusp: Magnetic Structure and Dynamics -- Magion-4 High-Altitude Cusp Study -- High-Altitude Cusp: The Extremely Dynamic Region in Geospace -- Magnetosheath Interaction with the high Latitude Magnetopause -- Cluster Observes the High-Altitude Cusp Region -- Low-Frequency Plasma Waves in the Outer Polar Cusp: A Review of Observations from Prognoz 8, Interball 1, Magion 4, and Cluster -- Multiple Flux Rope Events at the High-Latitude Magnetopause: Cluster/Rapid Observation on 26 January, 2001 -- Energetic Electrons as a Field Line Topology Tracer in the High Latitude Boundary/Cusp Region: Cluster Rapid Observations -- Energetic Particles Observed in the Cusp Region During a Storm Recovery Phase -- Coupling the Solar-Wind/IMF to the Ionosphere Through the high Latitude Cusps -- Spatial and Temporal Cusp Structures Observed by Multiple Spacecraft and Ground Based Observations -- Observations of a Unique Cusp Signature at Low and Mid Altitudes -- Cusp Modeling and Observations at Low Altitude -- Simulation Studies of High-Latitude Magnetospheric Boundary Dynamics -- Cusp Geometry in MHD Simulations -- The Magnetospheric Cusps: A Summary.