There were a number of records set at Domino Day 2008.

I thought the scene of the last 45 seconds or so, showing a field of dominos falling in parallel, was particularly interesting. The curve that defined the leading edge of falling dominos was not a straight line, and it changed shape a little — the speed of propagation through a line of tiles is not constant. With identical tiles it should depend on the spacing, which would dictate the time it takes for one falling tile to hit the next and the speed with which a domino strikes its target. But wile a larger spacing means the tip is moving faster, it also strikes at a lower point, which means it exerts a smaller torque to get the next tile to fall, so it wouldn’t be a simple relationship. You could also change the mass for another variable in the domino wave equation.