I'm very intrigued by the sources of peoples user names. they are a new form of name giving such as house names and boat names and CB 'handles'. Also the fact they obviously having meaning to the person they belong to but the meaning is completely not obvious to anyone else. Not really a question I know but I'd be interested on anyone else thoughts on the subject!
My name's Garry, so as a shortened version I get called Gaz or Gazza. My mam (along with others) sometimes extends my shortened name (!) to Gazzawazza. It rhymes, and I happen to like the sort of zig-zag sound of it. It also has a bit of my surname in it.
Mine is simple, easy to remember and obvious to those who know I am actually the mother of five children. All grown-up now (allegedly!). I also use another name relating to the number of grandchildren I have, and a third which is appropriate because I live near Blackpool.