This 603 x 800 JPEG image has a large blank space toward the left, for desktop icon placement. This is a close-up of a nudibranch, species Chromodoris coi. For more detail on this species see this page linked from the nudibranch gallery.

If you are using windows '95 or '98, after picture is loaded right-click on your mouse and select "set as wallpaper" with the left mouse button.