i think usernames suck, once you pick it, you're stuck with it for life
on some sites i picked my username all the way back around 2005, fifteen long years ago... luckily I didn't pick an embarassing name or anything like that (I'm looking at you, Phil "OMGClayAiken" Galfond LOL)... but still, the name I picked 15 years ago might have been relevant in my life back then, but today its like I'm a whole 'nother person with totally different interests and attitude about life. The name I picked then has zero meaning for me now. They should allow a username change every few months or so, for this very reason, however I don't think the major sites like
poker stars have ever allowed username changes, and don't even think about signing up for a new account just so you can get a new username... because that is illegal per the terms of the site. Lovely. (Edit: perhaps I'm incorrect, someone indicated in a previous post that you can indeed change your username on stars, but since I'm a "free" American and banned from
real money play on Stars by my own damn government... yeah.)
I think
ignition has the best idea, just don't have any usernames and give everybody a random number which changes every time you log in so nobody can get a read on you and so nobody can use a HUD to keep track of you.