1024X1024 seems to be the preferred Playbook wallpaper size. Feel free to post more 1024X1024 wallpapers here:
http://i606.photobucket.com/albums/t.../1024X1024.jpg
http://i606.photobucket.com/albums/t...eaTurtlePB.jpg
http://i606.photobucket.com/albums/t...clownfish2.jpg
http://i606.photobucket.com/albums/t...TurtleFace.jpg
http://i606.photobucket.com/albums/t...-Sunset3-1.jpg
http://i606.photobucket.com/albums/t...aradiseHut.jpg
http://i606.photobucket.com/albums/t...024PierTwo.jpg
http://i606.photobucket.com/albums/t...ingTurtles.jpg
http://i606.photobucket.com/albums/t...gramIsland.jpg
http://i606.photobucket.com/albums/t...4HDRIsland.jpg