At least two members of the private beta who'd like to participate mentioned getting a message:
You must have at least 5 reputation on ExpressionEngine to ask a question.
Is this indeed the case? Seeing as we're trying to promote the site and help committed members get active in the private beta, this would be a significant obstacle.
If there is such a limit, what is the simplest way for the user to gain enough reputation to ask a question?