No, probably not what you were thinking, but a useful delight that has finally provided a solution to keeping my 180mm steady - at least for horizontal shots, and verticals would just require a slight adjustment of the thing.
In short, I am making use of the cyclists who have spawned an industry here in the northern part of the isle. I wandered into one of their many boutiques this morning and enquired whether, perchance, they had a scrap inner tube from one of their wonderful flying machines. The chap said sure, and without asking why I should want such a thing, he pulled one out of his bin and gave it to me.
The iPad gem enclosed shows the complex mechanics: one length of carefully cut tube, draped over the non-moving part of the lens, and then tightened to flavour with a rolled up rubber band. A second band, treated in similar manner, completes the item making it both neater as well as providing a spare part should the upper band collapse with excitement at some stage.
One grips the suspended "strap" high up, and braces the top of the thumb and forefinger against the base of the lens, and it's steady like a rock compared to holding the lens with the hand.
I may speak with Nikon about franchise.
Perhaps I can invent a similar device for holding the iPad as camera.
:-)