Another good reason to create albums surfaces in the iLife set of applications: iMovie, iDVD, GarageBand, and iWeb all display iPhoto albums in their photo media browsers.
Have a batch of photos you want to use in another iLife program? Rather than searching through your library using those programs’ media browsers, first stash the photos in an album. Then, choose that album in the other iLife program.
iPhoto album support is also built into other programs, including Mail, Mac OS X’s screen saver, and Apple’s iWork programs.