Justin Williams, a fellow developer, has put together a quite nice and extensive list for Mac developers (and/or power users). The list ist huge and contains quite a few gems for developers. If you want to learn about new software and also some useful websites this is a nice start.
Justin also co-hosts the IRQ Conflict podcast, so he included some interesting audio soft- and hardware. I don’t plan on podcasting so that is not really that interesting to me at the moment, but if I ever were to start podcasting this would be my starting point to gather information.