I've got one. I use it on my Bessa R and R2a cameras. I don't have anything to share yet but I will when I get the film back.
I have made a couple pinhole body caps for my LTM cameras and liked what I got from those.
The Skink appealed to me for several reasons; the main one being that the pinhole itself is much better than what I've been able to produce and I hope that means less diffraction artifacts on the negs.
The Skink Kit I bought had several "lenses" included: a pinhole, a zone plate, and a zone sieve. Not quite sure waht that last one is but I wanted to try a zone plate so the kit made sense for me.
Also, the kit I got was made for M mount cameras which means that it included a very nicely machined LTM to M mount adapter. Since I use an R2a, I don't need an adapter that brings up specific frame lines.
I figure my exposure times either by using my handheld meter and multiplying the given time or, if I'm shooting in bright sun, letting the camera meter guide me. With 400 speed film I can get fairly short exposure times and mostly not worry about reciprocity. If I'm shooting some slower film or in any other light than bright sun, I will add time. And bracket.
For exposure times of less than 2 seconds, I don't correct. For longer times I do.
I also can recommend this program:
http://www.pinhole.cz/en/pinholedesigner/
It has been very helpful.
I generated a chart with it that tells me times for my aperture based on metered readings at f/22 and the film I'm using.
Rob