I thought this was an interesting article. Especially since I heard David Kuo (who also works for the fool) saying yesterday morning on BBC London that he didn't think credit cards could do this because they are an unsecured loan.
www.fool.co.uk/news/your-money/2008/10/29/more-pain-for-homeowners-in-debt.aspx?source=uemfoleml0010 038