iPhoto: CREATING MULTIPLE LIBRARIES

If you have a huge iPhoto Library, you might want to create multiple libraries, and then you can decide which of these libraries you want to open in iPhoto for today's editing. Here's how: Just hold the Option key, then launch iPhoto. When you do this, a dialog will appear asking you if you want to create a new Library, or open an existing Library. If you want to create a new one, click the Create Library button and a new separate Library will be created. The next time you open iPhoto, you can decide which Library you want to open by simply holding the Option key before you launch iPhoto (you'll get the same dialog again).