Ever come across one of these as you strolled through the Park?They are ubiquitous on Main Street, especially all around the Hub. This is a plughole for a parade post/pole. The rubber plug in the middle of the hole is extracted and a pole is inserted into the hole.
In 1987, Adventure/Frontier Attractions hosts and hostesses would join their counterparts on Main Street for a parade shift. This shift meant that you wouldn't be spieling through the Jungle or waking up Jose over at the Tiki Room.
No, you were assigned a flashlight with a colored cone and sent over to a section of the parade route on Main Street, usually around two hours before the parade's scheduled start time.
You were going to be herding guests at the Main Street Electrical Parade.
If you'd been around a while and "knew the ropes," you would be sent to a locker to retrieve ropes, bones, a pole cart and poles. 
You would then haul these items over to Main Street long before the parade was scheduled to commence. You and your crew would then start to lay out your ropes and poles. You would use the them to create traffic walkways or block off certain areas so that guests could be seated in advance of the parade.
Upon arriving at Main Street, you would open up your cart and throw your rope "bones" into a planter.
You would bring along with you certain lighted directional signs, too, that helped tell guests where the roped traffic areas were leading them. You can see a couple of the directional signs in the photograph below (taken of the planter on Matterhorn Way near the east side of Sleeping Beauty's Castle). 
The photograph also shows the carefully wrapped (and labeled) rope "bones." If you put the wrong rope on the wrong bone, the next parade crew will be faced with a magnificent jigsaw puzzle when they try and lay out their roped-off areas. It happened to me plenty of times.
Above is a close up of one of the bones from a recent pre-parade set up in August 2008.
And here is one of the posts (again, this is on Matterhorn Way, on the southeastern side, nearest to the fountain with King Triton). All the parade ropes are pre-cut and pre-measured so that they fit tightly between the two (proper) poles to which they are supposed to be attached. Get the wrong rope and the wrong pole and you'll end up too short or too long!
Parade crews usually get this process down fairly quickly, and by the end of the summer you literally "know the ropes."
After the ropes and poles are set up, the parade crew spreads out to several stations along the traffic areas. They then begin waving their arms (and coned flashlights as dusk turns to night) and verbally telling guests the proper route to take. You've seen this done a hundred times, I'm sure. Quite an orchestrated event.
I used to enjoy getting all the guests to sit down (especially those with the seats in front, closest to the parade route). In the 1980s, Disneyland had strollers with handles that collapsed downward. I would help collapse strollers (so their canopies would not block the view of the guests seated further back) and would make sure that the one guy from "out of the country"---who insisted on standing up at the curbline (while 500 angry guests glared laser beams into the back of his head because he was blocking their view)---was able to understand my nonverbal cues telling him to SIT DOWN!
It always amazed me that 750 to 1000 people could be seated in an area waiting for a parade and ONE guy (invariably in the front row) would insist on standing. What planet do these people come from? Is it o.k. in other cultures to block the view of your neighbors since you "got the front row???!" I made damn sure it wasn't o.k. at Disneyland (and I'm convinced that I saved many people from being stoned by angry mobs in the process!).
After the parade was over, while the guests were stampeding for exits or other parts of the Park, the parade crew would quickly break down the ropes and poles that they had put up earlier. It is vital to put the right rope back on the right "bone" and then back onto the right "cart" during this process, as noted above.
The Day Custodial crew would then follow with a team of sweepers (and often motorized vacuum cleaners) and clean up the post-parade mix.
All in a day's work at the Magic Kingdom (the original Magic Kingdom, that is).
