I found a really interesting site during my morning review of financial news.  I regularly review the Financial Times website at ft.com.  On there they have a link to the MBA GYM.  This is a free service of ft.com where you create an account and can test your knowledge on subjects like corporate social responsibility, leadership, marketing, and financial analysis.  If you have any interest what so ever with business and business related topics, and you like to give your brain a workout, then I encourage you to check out this site.