Multiple Libraries in iTunes 7; Multiple Libraries in iPhoto

Via Lifehacker, a very, very useful tip for Macs.

Hold down the Option key while launching iTunes or iPhoto and you can choose from among libraries. (Keep holding the Option key until the dialog box opens.)

This is great for dividing your music or photos into separate collections (I don’t for music, but do for photos).

The iTunes tip works in Windows, too: Hold the Shift key while launching iTunes.