Pickle forks for actual pickles
It has recently come to my attention in the catbox that there are some people who don't know what a pickle fork is. It is my civic duty to correct this grievous oversight in today's education, hoping to bring us back to a more civilized time. While a number of you doubtless handle pickles with your fingers, as is of course also proper, I would surely fall into a dead faint at the sight of someone handling a pickle with a toothpick or, heaven forbid, tongs.
A pickle fork is a small, two- or three-tined fork used for serving pickles. Smaller than a dinner fork but larger than a seafood fork, a pickle fork allows easy and sanitary extraction of pickles from pickle brine without getting one's fingers wet or contaminating the other pickles. One of two innovations to the traditional fork design make a pickle fork ideally suited for this task, as pickles are smooth and slippery inside and would slide off the tines of a regular fork. This is how the barbarous toothpick gained popularity, the wood provides its own friction to hold the pickle.
The first, and more commonly seen, option is to flare the tines of the pickle fork slightly outward to the sides. This creates an upward slope the pickle would have to slide against to fall off the fork. In the case of the three-tined pickle fork, the middle tine remains straight.
The second option is to add dull barbs to the tines of the pickle fork. This works in a similar manner to a fishhook or arrowhead to secure the pickle. The barbs, again, point outward to the sides of the tines and three-tined pickle forks leave the middle tine straight and plain.
In either case, the pickle may be removed from the fork with a gentle shake (for the amateur), or by sliding the pickle across either the rising edge of the plate or an item of food (for the expert). The pickle should not be eaten off the pickle fork! The pickle fork is for serving only. Pickles are to be eaten with fingers, or (for the bourgeois), in a sandwich.
Pickle forks in automotive mechanics
There is also a tool called a pickle fork used in automotive mechanics, although it looks more like a tuning fork than a pickle fork. The major distinction in appearance is that the tool's tines flare in, rather than out, which would of course make it useless for securing a pickle.
The pickle fork is made for separating ball joints, tie rods, Pitmon arms, and other such parts held firmly in place by friction around a shaft. The tines are sloped — thin at the tip, thick near the handle — so as it is hammered in, it acts as a wedge to dislodge the part. Lubricating the tines is recommended prior to use to avoid damage both to the pickle fork and the car parts.
A standard pickle fork is pounded on the "dumb end" with a hammer, and there is also a version that attaches to an air hammer.
Picklefork Deck
Thanks to Rubyscooter for mentioning that some ferry boats have a structure called a picklefork deck, narrow levels extending above the end of the car decks like two prongs.