In the last video of his course on Convolutional Neural Networks, Andrew Ng was discussing using ConvNets on 3D input data. He mostly discussed cat scans, but also mentioned you could treat a movie as 3D data and run a ConvNet on it (where the z axis is time, i.e. the # frame of the movie).
I find this pretty fascinating. I'm just curious if anybody is aware of anybody doing something like this in practice, and what they accomplished.