Usernames are funny. Pick something unique and interesting so you stand out and then chance it that you’ll ever be able to get that again. In the early 90’s I ran through a variety of screennames because of just that – pick something random and then be out of luck next time. I finally oped to use my full name everywhere. As one of the early twitter users I’m often asked why I didn’t opt for @sean or @s and while I could have gotten @s by the time I got there, 120th person to sign up or so, @sean was already taken. And if I’d been using only “sean” as my name elsewhere that would have been problematic for sure. @s is amusing but doesn’t map to anything. Even on ello @s and @sean are already gone but I easily got @seanbonner. That’s not to say “seanbonner” is in small demand. There are a few other Sean Bonner’s out there who I know I curse me as they regularly sign up for these places a year or so after I’ve laid claim and are stuck with “mrseanbonner” and “therealseanbonner” or “seanbonnerplussomerandomstringofnumbers.” There’s also someone out there who sees oblivious to both the concept that there are any other Sean Bonner’s and also that emails are specific, because I get mail for him about once a week because he’s always putting my email account on job applications and family correspondence. I’ve talked to his sister, his aunt and two of his cousins now who are quite confused as to why their little Seany gave them my email.