From the White House blog:
Today, the President invited everyone to use a new feature on WhiteHouse.gov called “Open for Questions” to ask a question about the economy and rate other questions up or down. Then, on Thursday morning, the President will conduct a special online town hall on the economy and answer some of the most popular questions and the event will be streamed on WhiteHouse.gov.
Voting and question submission will close at 9:30 AM EDT on Thursday. President Obama will hold a live online town hall will be at 11:30 AM to answer some of the most popular submissions.