Let's say you're interested in ghosts, but haven't had any luck photographing them on any of your nocturnal visits to local cemeteries and abandoned insane asylums. The ghost-hunting guys on TV seem to capture plenty of ambiguous images (in between surprised looks and spooked "What-was-that?" exchanges), so why can't you?
Fear not; technology can help you easily fake ghost photos, though it comes at the cost of making it harder for serious ghost researchers to do their jobs...
http://www.livescience.com/17029-fake-ghost-photos.html