Working on swing tempo seems to be the latest thing in golf instruction. First there was the Tour Tempo (see a review here) and several devices which are, essentially metronomes.
The latest in this idea is the SwingSong. The idea is that you watch the DVD until the image of the golfer swinging is ingrained, and listen to the CDs of original music to get the rhythm into your head.
In a way, it kind of reminds me of the old sybervision video training aid.
But I think there’s something to all of this. I often have a tune in my head when I’m playing my best. It’s usually a 3/4 beat and kind of humming the tune along as I play.