CNBC’s Million Dollar Portfolio Challenge has begun! Thinking of selling your business and investing the proceeds? Participate in this challenge to see if that is wise (not the selling, but the personal investing!). Begins today, 9/19 and ends 11/25. 1st prize: $1 million. 2nd prize: 2012 Maserati. Go to www.milliondollar.cnbc.com for details.