So, why do I use Pling? I've been Pling since first year of my undergraduate degree - it's a bit of a boring story, but I'll tell it anyway ;) Basically, I got introduced to the people I became friends with by a guy I had a mutual acquaintance with. For a while during my year out I'd been called Madge, but I'd decided I didn't like that. However this guy knew me as Madge so that's how he introduced me. So the first thing I said was "No, I'm not Madge, I'm Margaret". And they called me "Not-Madge" for a week or two. Then, being geeky types, they started to call me "!Madge" (ie "Pling-Madge", pling being the name of an exclamation mark, and it means not in C). "!Madge" is a little unwieldy, so it got shortened to Pling after a couple of days. And it's stuck for the last 9 years or so.
When I started spodding on MBA4 I was called Penguin, coz penguins are cool - but then when Snowplains started up I wasn't allowed to be Penguin on there, as it would be confusing (all the staff ranks are named after penguins, and in the help files it will frequently say 'Penguin' where it means 'staff'). So I just picked Pling coz it was my nickname anyway. And now it's almost as much my name as Margaret is - I answer to it in the street, I use it whereever I can online. But I don't use it at work, I've never even told people, partly coz I would then have to explain C, talkers etc. Oh and I've never explained to my parents, although they know that some of my email addresses have pling as the username.