Although most fly anglers (including myself) most often choose between a succession of snappy single handed pulls -or- the double handed "hand over fist" or "milk the cow" retrieve, there's a useful variation of the single hand strip that I call the "shock and stop" retrieve. It works on virtually all gamefish species under the right conditions, from deep offshore rips and shoals to albies on Vineyard Sound. As I recall, I first-casted a nice albie on a silverside pattern from Larry Backman's Mako last year at the Boneclave using the "shock and stop" retrieve beneath busting albies in the rip.
I also enjoyed a 7 keeper day on the Billingsgate Shoal fishing deep with 444 QD lines and very large sand eel patterns. The wire liner's were getting fish up to 40# using small jigs and wire on the shoal, so we ran out there with deep lines and flies. To keep the flies down on the wind-drift through the line of birds working the bait, we limited the retrieve to a hard jolt, then a pause - repeat. This kept the fly low in the zone and in the face of larger fish. The results were phenomenal.
Another location I've enjoyed success with this technique in on the Salisbury side of the mouth of the Merrimac where the currents are fast and the waters are deep on the beginning of the ebb. This is a good time for fish to stack up behind current breaks like the "pick", the short jetties, mussel beds, and the pronounced rockpiles that make themselves visible during low tide.
The technique also allows intermediate lines to fish very deep without changing to fast sinking lines.
On a releated note:
I have high hopes that in addition to it's effectiveness in the Northeast, it will be a contributing technique to the untangling of the relatively new fly-fishery for giant chinook salmon in the saltwater of the pacific northwest. Although the coho, chum, pink, and at times sockeye salmon are eager to take the flies retrieved in the ocean, the chinook tends to defy capture in the traditional strip retrieve manner. Tyler (the Spey casting machine from the Spring Native Mini-clave last week) guides from Langara Lodge on Vancouver Island during season. I hope to visit him one of these days to test such theories!