Where do you store all your digital photos? iPhoto, right? Now you can have multiple iPhoto photo libraries. From Alex in Mac360. The easy way:
Press the Option key while clicking the iPhoto icon in the Dock (or by double-clicking the iPhoto icon in the Applications folder). What you get is a pop up dialog box. Click to Create a new iPhoto library (which is safely stored next to your default library), or click Choose to select a library, or click Other Library to look elsewhere for an iPhoto library.
Excellent tip. It also works for iTunes 10.1.1. Multiple iTunes music libraries.