After digesting the news that Sal Sahogian has left Apple, we discuss a number of use cases for automation on the Mac and iPhone.
Hazel makes folder actions infinitely more powerful
Rob's Keyboard Maestro macro to bypass slow Archive Utility
Can do things like move and click the mouse, find buttons, and so much more
Script Editor (free, built in) or ScriptDebugger for working in AppleScript
Terminal (shell scripting) is an automation tool, too.