The present paper arose from a symposium at the 9^th International Conference of the Orthopterists' Society held in Canmore, Canada, from 14-19^th August 2005. Most of the major groups working on locust phase polyphenism were in attendance ^{(Table 1)}, offering the opportunity to review the rapid progress that has occurred in this field over recent years. To maintain momentum in this research, areas where results from different groups are at odds were debated, and ways to reconcile such discrepancies proposed. The symposium also provided researchers with a forum to consider how to coordinate core facilities and resources across laboratories, to make best use of national and international funding opportunities. Participants presented their results spanning a range of aspects of phase polyphenism research: molecular analyses, physiology, ecology and phylogenetic reconstruction of the evolutionary history of phase change. The symposium was followed by a detailed discussion session, attended by members of the audience as well as the symposium speakers. The present paper provides a synopsis of that discussion and is structured according to the major issues considered. Unless otherwise stated, the paper concerns the desert locust, Schistocerca gregaria, which has been the subject of most of the recent research.