Think of all the designers, engineers, technicians, etc. that worked long hard hours to achieve the best possible quality image. Now, with a little cardboard, tape, balse, etc., we can degrade that to the level of a kids toy.
That said, I love my LensBaby on my Nikon F - great fun!
And I love my Spiratone Portragon. I have a long-standing plan to mount the lens from an Empire Baby in a Nikon body cap. Part of the Empire Baby's charm is from the curved film plane giving edge to edge sharpness (a relative term) in the horizontal direction and a terrific edge blur in the vertical direction. Rounding the film gate with a file isn't something I really want to do to a Nikon.
You got me all excited thinking someone ruined their D3 but cutting it open, gutted it, putting in a pinhole and a primitive film advance.
What you linked is called "TTV" through the viewfinder. It's not new. Hmmm you could even liken this to the 35mm DOF adapters a lot of people use on their video cameras and even their super 8 cameras sometimes.
I confess that I was one of the early "TTV" adopters back in 2006 AND I was primarily a film shooter. It sprung out of a desire to use a couple non-working squareshooters (A Brownie Starflex and Duoflex) that held sentimental value for me and the love of the non-digital framing and 'schmutz' (left the mirror and glass untouched).
I had several contraptions - one to attach a digital cam for immediate results and another to attach my film cam. My 'contraptions' have been copied and modified and I admit it's funny to see what others have come up with.
Always got stares and curious questions ("what kind of camera is THAT!?") and I did find it very enjoyable, but limiting in many ways. In the end, I moved on to medium and large format and have never looked back. To each his own I suppose.