I have and use many usernames (according to the context of the site). On MusicBrainz I go by AzoreanGigolo my profile here which I'm pretty sure I can't change (or can I?).
In retrospect, it was a lame choice for a handle (I was using this one @ webcam-girl sites at the time and while being asked for a username I glanced over and on TV there was Richard Gere playing a gigolo — hey, that would be pretty cool, I thought).
My recent username on most sites, as on MetaBrainz Blog and BookBrainz for example, is now AzoresOne (a play on "AirForce1", sorta sounds like it doesn't it? ). I'd rather prefer and wanted to use this (latest) one, sorta too late now I guess, but I opted to go with the my MB user profile name, so people can know who... [everything jesus2029 said] <- how does one tag somebody à la Facebook?
This is mainly a introductory note — sayin' hi to all. Hope this issue gets streamlined. Rock on!
*Ahh, finally managed to get my gravatar working. Thing is it had to be 128 px square or less! One can hardly make out it's the Vitruvian Man