I just want to share some great looking wallpapers I found at deviantart.com that uses Ubuntu logo in its design.
Desktop wallpapers can also serves as identity as well so show the world (at least people around you) how Ubuntu you are with these wallpapers.
Here are some good stuffs I found at deviantart.com ( in no particular order).

1. Ubuntu Dragon by Kodein

Yellow-red Dragon and Ubuntu Logo

and Ubuntu Dragon by ~dzerox

Blue-eyed Dragon and Blue Ubuntu Ball (no pun intended)

2. Ubuntu Metal by fibermarupok

Tough Ubuntu

3. Ubuntu by snn-engn

Ink Stain Ubuntu

These are only a few from many good stuffs in deviantart. I'm sure you can found what you're looking for there.

keyword : ubuntu logo wallpaper