! Good Tips for wallpapers: !

You can use Panorama (on ovistore, free) to create extra wide (4 desktops) wallpapers.

Resize (with cut function -) ANY photo on your PC to 3200x480 and use (including the Panorama shots * Use Photoscape softare to crop * Assign ratio size ) WPCreator (application manager) to make four wallpapers with continuous slide.

Use "Live Wallpaper" (application manager) and install "Xscrensaver" too. Offers a lot of build-in animated digital walls, slideshow, take videos with your n900 an put them like wallpapers (with mute sound!)
for live wallpaper is best to overclock the CPU to 805.

- if you can't find this app. go to application manager and add the maemo-extras testing/ devel catalogues.