The E. & F. White Conference held in Sydney in December 1999 brought together expertise on a range of interference mitigation techniques from CSIRO, Australian and international industry and universities. Key goals were to enhance the understanding of techniques and their inter-relationship, to increase awareness of advanced technologies such as software radios and photonics, and to foster a cooperative approach to the development of interference mitigation techniques. The foremost application in mind was the square kilometre array (SKA) and the need to find ways to develop a hierarchical scheme for removing unwanted signals from astronomical data. This paper gives an overview of the topics discussed at the conference and summarises some of the key ideas and results that were presented.