I have found some great wallpapers simply using Google Images. You can not only search for the specific keywords you want but using the advanced options you can narrow the results by entering a specific resolution - 1024 x 768 - which will find the perfect size for you iPad. Try it out, keen to hear how others find it

My site, ipad backdrops - the definitive collection of quality iPad wallpaper, has HD wallpapers that are all 1024x1024, which means they look good in both portrait and landscape. I've cropped many of them personally so you can't find a lot of them any where else.