linking several sites for iPad walls 1024 x 1024 "rotation" ready.
http://www.ifullscreen.com/
http://ipadwallpaper.org/
http://www.ipad-wallpapers.com/
http://www.wallpapersipad.com/
a couple of these you can reach directly thru Safari...and when you click on an image...the img will open in a seperate "tab"...u can save the img directly with a long press.