Oxygen is the team behind the beautiful icon sets you will get to experience in KDE 4.0 when it is released sometime this year. The goal of Oxygen icon set is to create a set of icons for use on the desktop which are beautiful, support usability and accessibility and in a way, better fulfill the needs of the users.
The Oxygen team has announced a contest. Put your creativity to task and create a wallpaper. The wallpaper can be of jpg jpeg bmp gif png svg svgz formats. The theme for the wallpaper you create can be any of 3D art, vectors, photos, and pixmaps and it can be of any standard wallpaper dimension but bigger the better.
Once you have created the wallpaper, upload it to their website. If you are lucky and your wallpaper is selected, it will be included in the wallpapers that will ship as default set in KDE 4. More details here.