I spent several summers as a server in various restaurants during college. The problem with being a server that I soon learned about is that your biological clock can get quite out of whack. Any day that you are working is a day when you will miss a regularly scheduled meal -- but you will be looking at food the whole time. For those servers like myself who refuse to take breaks when they have something to do, this can be quite trying. Also, depending on where you work, you could be working until the middle of the night for a "dinner" shift. To cut a long story short, I couldn't get up in the morning for lunch shifts, and I needed fuel to keep myself focused at work.
Then I found out about Chocolate Coke.
There is an official soda fountain way to do this (see Chris-O's excellent vanilla coke writeup for more on this), but the vast majority of my chocolate coke experiences were of the quick and dirty variety. The purpose was tasty caffeine. I am not a fan of coffee, and I needed something cold that I could drink quickly in the summertime. I'm sure this isn't the healthiest solution, but when friendliness is money, caffeine is your friend.
My recipe is simple. Fill a glass with ice. Add coke. Then add Hershey's chocolate syrup, maybe a few ounces worth. Pour this mixture into another glass and back again a few times to mix. Add a straw. Sip, but don't enjoy, because your three top in the forties wants their appetizers, you have to get more ice, and oh wait -- you just got double sat. If you're as sensitive to caffeine as I am, a couple of these can keep your motor running for an entire shift.