I have a cell-phone and I do not answer unknown numbers.  Someone called at 10:37 AM on 09/30/2013 and did not leave a message.  This is the third time they have called my number in the last month and left no message.  My phone number is registered on the national Do Not Call List (https://www.donotcall.gov/default.aspx) and I reported this call to them.  I wonder if this is another scam company!