Here's a nifty trick for those of you running OS X Mavericks. Apple has included some beautiful nature photos to be used as the OS' screen saver options. With a little digging, you can use them as desktop wallpaper, too.
Lifehacker points out that the 43 photos can be found by navigating to /Library/Screen Savers/Default Collections/ from the Finder's Go menu. From there, you're all set. I like to open the Desktop and Screen Saver preference pane and drop my chosen image into the well. Have fun.
Apple OS X Mavericks