I have no idea if this had been done already, but I felt I should give it a go anyway. It's relatively simple events with Space Guy's Wrench Events v3. Anyone could replicate it, although you have to define each dominoes name and target individually, so I didnt want to do loads. Enough jabber though, here's the video, kindly demonstrated by Azazel and Devastator.
http://www.youtube.com/watch?v=a1Ody8Gs1P4If you would like to make your own, I took a pic of the event set up on the start and follow up bricks.
Domino 1
Wait for - Touch (1ms)
Trigger - Auto - 2 (1ms) - This sets the next target
Door - All boxes ticked (100ms - this is how long the domino disappears for)
Domino 2 and after - Make sure to change the event name and target for each brick

Wait for - Triggered (1ms)
Wait for - Time (1ms)
Triggers - Auto - 3
Door - All boxes ticked (100ms)
If you have any prior experience, you should be able to use that straight away. If not, keep playing, you should get it. Also, looking back at it, I believe you could stick a touch trigger on all the other bricks too so you could initiate the dominoes at any point and have it work fine.