The secretory accessory gland proteins (Acps) of male flies have been described as the "currency of chemical communication between males and females", attracting the interest of cell and evolutionary biologists alike. In the June 19 Proceedings of the National Academy of Sciences, Swanson et al. describe a comparative EST approach to exploring the evolution of accessory gland genes (Proc Natl Acad Sci USA 2001, 98:7375-7379). They isolated accessory gland ESTs from Drosophila simulans and compared them with the related D. melanogaster genome. They isolated 212 independent genes, many of which were previously uncharacterised, amongst which 57 appear to be novel Acp genes. Comparison with the D. melanogaster genome identified 11% of genes whose evolutionary divergence appears to have been accelerated by positive selection.