Even the White House used Google Moderator to allow citizens to submit questions to President Obama for his town hall meeting on March 25, 2009.
Google Moderator lets you not only submit questions but vote on whether or not you like the questions that have already been submitted. In theory, this should sort out junk questions and present only the best questions for the town hall meeting.
There were 465,164 votes on 13,703 questions from 28,427 people!!
CALI presented a webinar on using this tool. (see post from May 6, 2009)
Professors go to: moderator.apps.com, sign in with their Google account, name the series and then email students this link.
Students then can submit questions and vote on whether or not they like the questions that have already been submitted. This can be used before review classes for exam in order to sort out what things professors need to review.