Sebastien Gaucher has cool tutorials on matte painting or digital manipulation of images using Photoshop, with step-by-step instructions on how to change a cheerful, suburban home into a haunted house, changing summer into winter, sunshine into rain ...
Awesome stuff! Link - via Sam-Diablo
I tried something like that with a picture my brother sent me of a construction site in the netherlands, which, as he wrote, somehow reminded him of the movie "Aliens" (aka "Alien II").
I "alienated" it a bit more... of course by far no match for mr. gaucher's image, but then it took me only 15 minutes :)
mouse over the image to see before/after)
It's in Alameda, CA Link
It a beautiful house, the owners worked on it for years to make it that way.