Although this dog seems to enjoy playing with it for his tail is always wagging!Please Register or Log in to view the hidden image! http://www.youtube.com/watch?v=4PcL6-mjRNk&eurl=http://www.stephenbainbridge.com/
I didn't want to post there about it, however there have been dog toys on the market for over a year that do exactly the same job. In fact they are built to be more dog friendly in regards to not having protruding cables, wires or jagged areas considering dogs have a habit of nibbling on things. (In fact one I saw was like a plastic disc you laid on the ground about 1 metre in diameter, the dog could drop the ball into a scooped out area which would roll onto a trigger. The trigger only extruded a couple of centimetre's, but it would wind down and then fire at speed enough to throw a tennis ball in the air. The invention itself was based upon the indoor Putting Mate, which has been around for decades.