NES in NES Cartridge

The stuff that some people come up with never ceases to amaze me. Take this guy for example. He put the NES inside an NES cart. It may look a bit clunky but the overall result to me just screams "brilliant". I just wonder how much work went into making it. Some may say this dude has too much free time on his hands and that he could put his time to better use. But we've already got enough productive people on this planet. Why should he waste his time and energy on actual productive things? I say let him and all the other gaming tinkerers out there keep hammering away, impressing us with little wonders like this one.