iPhoto sports a special Trash album that holds all your deleted photos, just like the Finder's Trash. And like the Finder's Trash, you can pull mistakenly deleted photos out.
Ways to recover photos:
Creating Multiple iPhoto Library Folders
Although there's little outward indication of this, iPhoto lets you create and maintain multiple iPhoto Library folders.
Reasons to create multiple iPhoto Library folders:
To create an iPhoto Library folder:
Switching between iPhoto Library Folders
So you now have two (or more) iPhoto Library folders. How do you switch between them?
Ways to switch between iPhoto Library folders: