Just a quick tip for anyone who’s interested. I was tooling around in iPhoto earlier today and noticed that the “Edit in external editor” contextual menu option was disabled. Though there is no preference exposed in the UI, the following command will tell iPhoto to use the GIMP:
defaults write com.apple.iPhoto ExternalEditorPath -string "/Applications/Gimp.app"
Feel free to replace that application with your editor of choice. That’s all for today!