You can now add your GAMER ID on your profile (it will show in the post profile too, see mine).
Just in case you didn't notice them...
Go to > Profile > Forum Profile to fill the text box with the GAMER ID you want.
Stealth Update from Andy: We've also added support for coloured usernames on the board, so your name will display as the colour of whatever group you're in. (Hint: It's the same colour as your name in the "Online Users" box!)