http://www.youtube.com/watch?v=P5f9bpaK04QDo all great danes act like this? Mine does the exact same thing. I thought it was abnormal behavior, but now that I've seen this video, I'm not so sure.
Not all, I'm sure, but many large breeds are known for goofiness. I had a German Shepherd who would act like that sometimes.
Mine does the same thing. There is one wooden spoon that freaks him out. Every time he sees it he barks and dances around like that.
That dog is fucking tripping balls.