Following the rabbit trail of that thread (all the paw questions) is a fascinating look at how really good questions tend to get really excellent answers. Of course, it doesn't hurt that it's an intriguing problem but the fact that the question asker adds a ton of pictures and information has to be the key in getting a very thorough and informative answer.
Even more interesting to me from a psychological perspective is the amount of time people are willing to spend on other people's problems when those problems are challenging and/or framed well. Interesting stuff.
For what it's worth, I had a golden retriever who liked to toot the horn of a little Fisher-Price train, so I bet a sound board would work. He always used his nose, which I think would be more likely to work on an iPad screen than paws.
Even more interesting to me from a psychological perspective is the amount of time people are willing to spend on other people's problems when those problems are challenging and/or framed well. Interesting stuff.