This isn’t exactly a resource, but I think it is important to keep your work environment inspiring. Smashing Magazine has a great collection of inspiring desktop backgrounds for your mac (or pc, if you haven’t seen the light yet.) Hopefully you’ll find one you like, or get inspiration to create a new one yourself.
Fat Car – by Erwin Wurm
artist & website: Erwin Wurm – http://www.galerie-krinzinger.at
Asylum 2 – by Tim Biskup
Cel Vinyl Acrylic on Wooden Panel
artist & website: Tim Biskup – http://www.timbiskup.com
Untitled – by Maria Hinze
artist & website: Maria Hinze – http://www.mariahinze.com
Head On – by Cai Guo-Qiang
artist & website: Cai Guo-Qiang – http://www.caiguoqiang.com/
Water – by Skopein
artist & website: Skopin – http://skopeindrawings.blogspot.com/
Untitled – by lichtfaktor
artist & website: lichtfaktor – http://www.flickr.com/photos/lichtfaktor/1483032641/
Walking Bike – by Max Knight
artist & website: Max Knight – http://maxknight.co.uk/
German Panther – by Hans Hemmert
artist & website: Hans Hemmert – Gallery Site