The famous Bliss.bmp wallpaper for Windows XP in a super high resolution format: http://www.shrani.si/f/2L/oL/2yFebWXf/bliss-600dpi.jpg.
A high resolution photograph of the space shuttle and an old Ipod that is visible through the window: http://www.nasa.gov/images/content/217432main_iss016e032313_hires.jpg.
A stunning photograph of Monument valley Colorado: http://www.listofimages.com/wp-content/uploads/2012/08/monument-valley-colorado-plateau-utah-usa-butte-panorama-clouds-nature.jpg.
This is the Burj Al Arab 5 star hotel in Saudi Arabia; this overlooks the Persian Gulf and offers the best hotel experience on the planet: http://wallpapersus.com/wallpapers/2012/08/Burj-Al-Arab-Hotel-Dubai-United-Arab-Emirates-1600×2560.jpg.
There are also many other useful images that are very suitable for your desktop. This one; an image of a giant tree that rises above the clouds like the Tree of Might in Dragonball Z is a rather unique image that is perfect for a personalised desktop: http://suptg.thisisnotatrueending.com/archive/5470279/images/1250393406498.jpg.
This artisic masterpiece depicts old and crumbling buildings. This would make a lovely wallpaper image on your desktop: http://0-media-cdn.foolz.us/ffuuka/board/tg/image/1335/66/1335665903778.jpg.
On the topic of desktop themes, here is a link to a Gnome Shell Tron Legacy desktop theme that would be perfect for any Linux user and Tron fan: http://half-left.deviantart.com/art/GNOME-Shell-Tron-Legacy-208220836. The Tron Legacy movie computers that used a version of the Sun Solaris UNIX operating system were very good indeed and the on-screen keyboard that was use to interface with the UNIX operating system was done very well indeed. There is more information about the Tron Legacy commands and systems here: http://www.riedquat.de/blog/2011-03-06-06.