News Scientists demo robotic 'third thumb' — get a gaming advantage with an extra appendage

So how do we go from this thumb to this sci-fi?
A+ for the reference! It's a good version, too. Aside from the weird incongruity of some sort of wireless network they're obviously connected to, while the plot revolves partially around payphones (or some kind of comparable public-access terminal), that movie aged pretty well.

To answer your question, I think we'd need to at least start by chopping off your hands...
 
Oh, and I was going to say that using the thumb for gaming seems pretty dumb. A much better approach would be to bypass the thumb and jack the electrodes (pretty much) directly into the machine.