gistfile1.hs

import System (system)
import System.Posix (sleep)
import Text.Printf (printf)

import Flickr.Monad
import Flickr.Types
import Flickr.Photos
import Flickr.URLs (photoSourceURL)
import Flickr.Groups.Pools (getPhotos)

image    = "/tmp/ubuntu-wallpaper"
interval = 10 {-minutes-} * 60 {-seconds-}

main = do
  urls <- flick getPhotoURLs
  mapM_ (\url -> display url >> sleep interval) (cycle urls)

display url = do
  system $ printf "wget \"%s\" -O %s" url image
  system $ "gconftool-2 -t str -s /desktop/gnome/background/picture_filename " ++ image

getPhotoURLs = getPhotos "556923@N24" [] Nothing [] >>= mapM url
  where url Photo { photoId = pid } = do details <- getInfo pid Nothing
                                         return $ photoSourceURL details PhotoSizeLarge