I recently spotted a thread on the Gearbox forums where someone had made some fantastic Borderlands themed Wallpaper. I asked him if I could share it with everyone here, and since he's keen on the game being a success (aren't we all?) he very kindly agreed!
I picked my favourite 3 (well, I thought they were all great, but I didn't want to pinch all of them!) and have added them to the wallpaper section of the site.
They're all currently in 1440x900 resolution, but I'm sure people of your calibre will be able to resize if necessary.
Here's a preview of the Lilith one:
(Am I allowed to say how miffed I still am at the PC version delay? No? Ok then...)