Most of you will already know this, but for those of you who don't. Your member title can be changed to whatever you want it to be (member title is the "Member" or "Sr. Member" or "Mod" that's under your avatar). If you go to My Controls ---> Edit Profile Info ---> it's the Custom member title, change it to whatever you want :)

But if you'd ever like to change your actual username, you will need to pm an admin and they'll do it for you, you can change it up to 3 times.

As I've found - and already abused :D