The magnificent set of snowflake photos by Russian photographer Alexey Kljatov (recently featured by kottke.org) make for some wonderful desktop images. Michael and I have both just recently updated our desktop images to these snowflake macros.
Michael's Razer Blade features an 800x640 display as the trackpad. A resized snowflake makes an ideal trackpad background.
Pro Tip: If you're trying to turn one of these images into a 16:9 or 16:10 wallpaper, Photoshop's Content-aware Fill (Shift+F5) is your best friend.