Partial support is requested for the Gordon Research Conference (GRC) on `Diffraction Methods in Structural Biology' to be held at Bates College, Lewiston, Maine from 7/13/2008 -7/18/2008. Structural Biology is a field which underpins our basic understanding of the molecular basis of disease, and hence of disease prevention. The diffraction of X-rays from crystalline samples is used to obtain information on the three-dimensional shapes of large biologically important molecules. This knowledge often allows both the function of the biomolecule to be defined and the mechanisms of action of molecular pathways relevant to human health to be determined. It provides the necessary information required to interfere with these pathways if they have undesirable outcomes (e.g. structure based drug design against cell cycle proteins which control cell division in a cancerous tumour). This GRC is the main forum in the United States for the presentation and discussion of recent advances in all aspects of diffraction methods. The 2006 meeting was very well attended and fulfilled a vital role in the field by allowing extended discussions between those actively involved in methods development from geographically diverse locations. ? ? The 2008 meeting will be chaired by Elspeth Garman (LMB, Oxford University) and Andrew Leslie (MRC-LMB, Cambridge, Vice-Chair) and will include presentations from many of the key software and hardware developers in the field. Sessions are also planned to discuss the challenges posed by membrane protein structure determination and on developing the potential of the many macromolecular crystallography synchrotron beamlines worldwide. An innovation at the 2006 meeting was the inclusion of very stimulating sessions on `Other Biophysical techniques' and on `Imaging methods of the future'. We plan two more such sessions for 2008 which will include talks on neutron diffraction, EXAFS, concurrent X-ray and on-line spectroscopy measurements, developments in electron microscopy methodology and X-ray diffraction imaging, as well as recent advances in research on the feasibility of single molecule imaging using a Free Electron Laser. There is a growing recognition that the use of such complementary techniques highly benefits the study of the increasingly complex assemblies of biological molecules now under investigation. ? ? ?