So you now have two (or more) iPhoto Library folders. How do you switch between them?
Ways to switch between iPhoto Library folders:
Hold down and click iPhoto's icon in the Dock to launch it and display the Choose Photo Library dialog. Click Choose Library (Figure 2.21, opposite), and locate the desired iPhoto Library folder.
With iPhoto not running, manually rename or move your main iPhoto Library folder, then rename or move the desired iPhoto Library folder so it's called just "iPhoto Library" and is located in your Pictures folder.
When iPhoto is not running, rename or move the iPhoto Library folder, launch iPhoto, and, when prompted, click Choose Library and locate the desired iPhoto Library folder (Figure 2.21, opposite).
Use the free iPhoto Library Manager from http://homepage.mac.com/bwebster/iphotolibrarymanager.html.
Use Rick Neil's free iPhoto Buddy (www.iphotobuddy.com), which gives you a simple interface for switching quickly among multiple folders (Figure 2.23).
Figure 2.23. Use iPhoto Buddy to switch among multiple iPhoto Library folders.