I have just discovered and started using the Ordinance Survey wallpaper as my desktop background. There is one per month and it has a fairly unobtrusive calendar at bottom right of picture. The pictures are gorgeous landscape and rural scenes.
If you'd like a look you can find them here:
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/
I wish they were available without the calendar as well because some of the earlier months are great scenes. Earler months are available here:
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2005.html
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2004.html
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2003.html
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2002.html
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2001.html
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2000.html
If you'd like a look you can find them here:
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/
I wish they were available without the calendar as well because some of the earlier months are great scenes. Earler months are available here:
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2005.html
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2004.html
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2003.html
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2002.html
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2001.html
http://www.ordnancesurvey.co.uk/oswebsite/freefun/wallpaper/archive/2000.html