Why is it that we give each other nicknames?
From Wikipedia:
A nickname is a descriptive name given in place of or in addition to the official name of a person, place or thing. Another class of nickname is the familiar or truncated form of the proper name, such as Bob, Bobby, Rob, Robbie,more properly called a short name.
A nickname is sometimes considered desirable, symbolising a form of acceptance, but can often be a form of ridicule.
In Viking societies, many people had nicknames which were used in addition to, or instead of their family names. In some circumstances the giving of a nickname had a special status in Viking society in that it created a relationship between the name maker and the recipient of the nickname, to the extent that the creation of a nickname also often entailed a formal ceremony and an exchange of gifts. Slaves have often used nicknames, so that the master who heard about someone doing something could not identify the slave.

I have always given people a nickname, mostly a different version of their name. My niece Jamie I call James, a co-worker I call Scotty Dawg, Julie becomes Jules and another of my friends is "Great-Scott"! Then I have a few friends that I call by their full name only.
Sometimes I follow a weird thing I picked up while living in New Zealand and that is to add an "er" in the place of an "a" at the end of someones name; Melissa becomes Melisser. Then my friend, who's last name is Cross, got the nickname of "Nelda Tuda".
Then there are the names I give people I see all the time but I never know their real name. Mostly these are people at the gym or people I see shopping in the same store as I do. These names come from some characteristic they have. At the gym there is "Salsa Sally" who must have some good music on her iPod, she gets on the elliptical machine and dances and sways her hips a lot! There is "Drummer Joe" who thinks he's on stage playing a drum set while he's on the stationary bike. There is the perfectly coiffed "Tina LaTina" in all her south of the border glory and her friend, "Winney Nguyen" her Vietnamese workout partner. I think part of their workout is flirting with the few straight guys that go to the gym.
Some guys there get the name, "Nike Boy", "Uppity Gay Bear" or the "Uber-gay power couple". One day at the gym I asked two guys how many sets they had left and one responded in a heavy german accent that they still had a lot more to do. They became "Hans and Franz". Oh, I almost forgot "Huff&Puff" the noisy guy who wants
everyone to know that he's lifting very heavy metal objects!
My buddy Ryan who works out with me sometimes is in lust with "Tat Daddy" or TD as we call him. TD is a hottie and bi-curious I think. He came sniffing around Ryan while I went to refill my water bottle! The other random guys are "hot-daddy", "hottie-boy" and occasionally "creepy-old-guy".
Here are some favorite nicknames of people I worked with years ago. One guy loved to mention to
everyone that his sister is the First Lady of Oklahoma. His nickname became "Michael Regina" (he is Oklahomo royalty after all, and Regina rhymes with something else....)

Then there was the the Ultra-Catholic I worked with whom we christened "Mother Inferior". When I worked in retail I had regular customer's "The Jello People" and the "Amazon Queens". Ask me sometime for the whole story on those two, pretty funny. LOL
At the country western bar here called the Round Up there was a guy who
loved to spin a lot while dancing, he became "Spinderella".
Should I use the old Viking custom and have a formal ceremony for the giving of someone's nickname?
What are some fun nicknames you all have come up with for people?