same-shade-on-checkerboard-with-shadow-from-column illusion

Years ago (2005!) I posted a picture that demonstrated probably my favorite optical illusion of all time, the same-shade-on-checkerboard-with-shadow-from-column illusion. Here is that post:

http://www.primordia.com/blog/archives/2005/03/it_cant_be_true.html

Now, someone went and did this in real life. The effect is even more profound and amazing.