When you're browsing through an album, look along the bottom of iPhoto's window; you'll notice other options besides Print, Slideshow, and Book.
Email This option gives you a simple way to attach photos to an email. Select the photos you want and click Email in the toolbar at the bottom of the window. iPhoto will ask you to select a compression size. (Do your friends want photos as large as you can make them? Do you have a dial-up connection, which necessitates small, highly compressed images?) Then, when you click Compose, iPhoto will attach the images to a blank email in your default email program.
Order Prints Much like Buy Book (in the Book window), this option connects you to an online printing service where you can select sizes and quantities of individual prints, and have them billed and shipped to you.
HomePage This option, which is related to your .Mac account, will be discussed in some detail in Lesson 13.
Desktop With this option, you can instantly change the Desktop picture on your Mac to the selected photo (usually controlled via your Mac's Preferences > Desktop pictures). This is a cool feature, but it's not easy to undo.