I know people try to make their children more independent (charging rent, telling kids to move out) but my father said, "I didn't have kids just to kick them out." My parents' house was always open to us for as long as we needed it. Their rule was that we just couldn't be lazy. Either you were in college or working. They figured it was a waste of money for us to pay for rent/food/utilities somewhere else while it was free at home. None of the 5 of us took advantage. We all held at least one job (usually more) or went to college AND held a job. We all lived at home until about 27 years old. None of us left with any college or other debt and several of us had plenty of $ for downpayments on a house.
So, my advice is to keep your home open to your kids. Expect that in this economy that they will be back. Consider this time a "vacation." The security for a child knowing that they can come back is priceless.