When Dr. Veilleux and I attended a workshop in Marseilles; the first ever results from integral field units were shown, from four different groups as I recall. All of them had the same problem: they were unable to remove the sky.
Dr. Veilleux and I shared a room and he still recalls how I woke up at 3am one morning to write up notes on how nod & shuffle might be used to remove the sky. I thought I was being quiet but I kept him awake (unknowingly) for the rest of the night. In the morning, I explained to Sylvain about IEEE papers I had read years ago where early CCD developers had used shuffling (they called it charge shifting) to detect several different families of charge trapping sites. I had read another paper which said that silicon wafers were getting larger and more pure, and just guessed that shuffling the charge up and down would reveal fewer trapping sites, since these are functionally related to bad columns, and devices appeared to be getting cosmetically cleaner as every year goes by. I foresaw a device that was much larger than the illuminated field of view along one axis.
At the AAO, we started developing charge shuffling in 1994, but our first good results were in early 1995. I wrote about charge shuffling attached to imaging and spectroscopy in 1994, 1995 and 1996. We have used variants of shuffling with imaging spectroscopy since 1995 using the instrument TAURUS. There are dozens of published papers on this work which continues to the present day. Our early attempts at nod & shuffle were not properly integrated into the telescope system.
A year or so later, being one of our foremost observational cosmologists, Karl Glazebrook foresaw how to exploit nod & shuffle with the multi-object spectrograph LDSS in order to obtain far cleaner spectra of high redshift objects in the Hubble Deep Field. Since that time, Karl and Bob Abraham have performed a series of lovely observations of high redshift galaxies in the optical, and more to the point, extracted new science from them. To my mind, they have reinvigorated observational cosmology in the optical no less, and both deserve full credit for pushing Gemini into doing the same.