Here's a complicated but well documented method for taking an iPhone from a unlocked state to a factory fresh state, so you can go on and upgrade to 1.1.1 if you've been testing unlocks. It works by refreshing the baseband firmware to factory default; meanwhile, bricking is supposedly caused by the altered unlocked basebands being only partially overwritten 1.1.1, causing a stew of code. *shrugs*. I haven't tried this fix yet, so I can't recommend it one way or another. But if your iPhone is already stuck at the activation screen (what people have been calling bricked), you might as well give it a whirl. What else could go wrong? *ducks*.
UPDATE: The iPhone "Elite" Team's Wiki has been updated with some weird writing indicating that this won't restore it to stock, and then some other writing indicating it would. This is why I'm waiting for the GUI version from the Dev team, even if I do appreciate the efforts of everyone working on this.