While I was visiting Johann's blog, I saw a new game for dogs. It can be used as an intelligence-enhancing activity, or as a way of feeding a meal. It's the Aikiou (pronounced IQ).
On Youtube there's a video clip of a Welsh corgi trying it out it. It's one of the better clips I've seen, because the dog seems to be unfamiliar with it and the clip shows the whole process of learning to use it, I think.