Not tDCS, but fascinating. Greg Gage @phineasgreg of BackyardBrains demonstrating a device that allowed one person to control the arm of another. I especially like his closing remarks,

This is what’s happening all across the world, electrophysiology, bring on the neuro-revolution.

See Also: Are you thinking what I’m thinking? The rise of mind control
The neuro-revolution is coming: Greg Gage’s neuroscience kits put research in the hands of the curious