OK, I think this used to be an option in an older version of OSX, but I can't find in in the latest version.
How do I bind a certain key (like F16 for instance) to run a Terminal command? I'd rather not install any additional services.
I just checked my 10.9.5 and 10.6.8 systems, and both have this under: System Preferences -> Keyboard -> Shortcuts
This allows you to bind a key to a command available via the menu, either globally (for all programs) or just a specific program.
If what you want to bind isn't a standard command, you can create an Automator plug-in that becomes available via the Services menu of a program, so that you can bind it to a key.