Speaking at the Citi Global Entertainment Media & Communications Conference, Verizon CFO Fran Shammo revealed that his company sold 4.2 million iPhones in the final three months of 2011. According to StreetInsider, Shammo said the company sees a 500 to 600 basis point drop on the iPhone moving forward, although no specific timeframe was provided. The number is more than twice the company’s iPhone sales figure for Q3; Apple sold over 17 million…