I know that the ability to change one’s username can be abused, but what if the SDMB would allow it, for a small fee? I think $3 would be a decent enough price and would prevent from having too many people request username changes. Plus, there’s nothing bad about additional revenue. 
Another way to prevent abuse would be to make any newly-changed usernames a different colour for a period of, say 45 days. For example, they could be red to let others know that the person recently changed their username. Kind of like how eBay puts a little icon (sunglasses, I think) beside a user’s name for a month or so after a name change. The only thing I can’t really think of is how to let people know what a poster’s previous username was. Maybe it could just be their choice to make a mention in their signature?
Lots of people have changed their usernames. It’s allowed after the 30 day trial, once you have paid the membership fee.
The process is described in one of the sticky rule threads at the top of this forum:
The procedure is to email one (or better, a couple) of the Admins from the same email you have in your user profile. And wait a week or so before trying again, in case they are on vacation.
Admins include Arnold Winkelried, Lynn Bodoni, Gaudere, TubaDiva and C K Dexter Haven. (Admins also include Ed Zotti and Cecil Adams, but they aren’t generally available for name changes.)
Oh damn. Thanks. I’ve been informed. 
blushes
We do want people to look at their user names with some thought, to find a name they’re comfortable with, and to stick with it.
Usually we allow one name change just for the heck of it, because people sign up with a name and find they’re not happy with it, that kind of thing.
After that initial change, you really need a good reason. We’ve changed names a second time when life’s circumstances changed, usually in negative ways.
Again, what you say and how you say it and the name you use for it tends to stick with you, so consider before you hit that enter key.
One of the more common reasons these days we get requests for user name changes is that someone has been highly critical or something or someone . . . and it has come back to bite them in the butt. Jobs and relationships of all kinds have been put on the line with this. More reason to consider before you send something, in whatever name you use.
And one other thing: more than one user name means all names get banned. This has always been true and remains true, even when you’re paying for the privilege of being here. That policy has not changed.
your humble TubaDiva
Administrator
Thanks to you both. I’m going off to make a request right now.