You may want to include photos in documents that you’re creating in Microsoft Word or other programs. It’s easy: just drag the image from iPhoto into your document.
If you use Apple’s iWork software—Keynote, Pages, and Numbers—your job is even easier. All three programs provide media browsers much like those in the iLife programs: access your photo library directly, search for a photo, and then add it to a document by dragging it from the media browser.
If you drag an image to the Finder desktop or to a folder window, iPhoto makes a duplicate copy of the image file. Use this technique when you want to copy a photo out of your library.