Currently, there is no in-game way to remove keys from being bound. No GUI way that I've found, in any case.

TAB is set as the Turbo key, as well as an auxillary switch on my joystick. I can turn the switch on and be turboing and then start talking, except if I'm doing a PM or auto-completing. Because I'll press TAB and the turbo will turn off.

Perhaps an option at the bottom of the key-binding menu, for 'clear button' and then 'press button to clear'? I'm sure there is a /command to do this, but it would be nice in the GUI.

Seconded, since he beat me to the posting. Grr.

You can do this: bind "tab" to be something arbitrary (maybe the fps command) and it will unbind the turbo from tab.

That's the only way I've been able to do it...

No, that will still be a problem. 'TAB' is still bound to SOMETHING. So now everytime I talk, the Frames-per-Second will appear and disappear, which is still annoying.

I know, I'm just offering you a quick fix until they give us a /unbind command.

/bind TAB ""

Actually there is a way to remove binds. Move your mouse over the key you want to unbind, until it's lit up but DON'T CLICK, and press the delete key. Problem solved.

the backspace key works as well arolte.

highlight the item you want to unbind with the mouse and press the backspace instead of clicking on it to bind it.