I found a pearl script at binaryhack.org that lets you mass-download images that are hosted at imageshack.us. All you need is the pearl script and the mechanize module to download images from imageshack. If you are running windows you need a pearl interpreter, PxPearl seems to work with this script.
You can edit the code that not only jpg jpeg are saved but also .pgn .bmp and every other image format you add there. They probably add support for more image hosting sites in the future.

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