Update (and shameless bump):
You can now sign up in game, through the petition system with the message starting @starphire. State your name, guild if any, squire, and coat of arms (remember to keep it simple).
@starphire: Hello! I'm <name> <surname> and I'd like to sign up for the Starphire Tourney. I'll fight for <name of your guild>, and my coat of arms is <your creativeness burp here>.
The GMs will approach me (hopefully) and tell me your info so I can put it here. You can also send them a private /tell - but remember to be courteous and ask whether they're busy first.
There's less than a week left, so hurry up!