We’ve done this topic before, when all there was was spacestationd. Which worked great, but it was a inconvenient to switch your background images very often and the process of doing so was ad hoc. Now we have found an application that does the same thing with what looks like a better algorithm and drag ‘n drop ease for changing images. Enjoy!
SpaceSuit is Spaces’missing feature: 1 different background image for every Space.
Now you can customize each Space with its own wallpaper and identify it quickly everytime you switch from one Space to another.