Personally, I know that I have been nicknamed by co-workers on several occasions - and anyone who works in an office environment and thinks they haven't been given a nickname is just fooling themselves. The nicknames I know of are:

Young Sarah - Which is pretty obvious - I work with a bunch of middle aged men and I (at the time) was a 20-something trying to figure it all out, and
Stompin' She-Beast - OK - this one was given within my first 2 years of employment, by a group of my peers, who had to listen to me moan and groan about all of the problems I was having with my boss. At the time, I wasn't confident enough to approach him with my issues and develop a way to work around it. So, instead, I would let my frustrations build up to the point of explosion then go to lunch with "friends" and let it all out - apparently with LOTS of GUSTO!