2. Boeing ( BA) designs and manufactures commercial and military aircraft. For the fourth quarter, revenue and net income declined 8% each to $16.55 billion and $1.2 billion, respectively. Metrics for the defense, space, and security (DSS) segment, which accounts for nearly 50% of Boeing's revenue, were superior when compared to overall operations. The segment's revenue and net income were $8.2 billion and $816 million, declining 4% and 2%, respectively. However, the company's operating margins were better at 10%, compared to 9.7% in the prior year's final quarter. Backlog at DSS is $65 billion at the end of the fourth quarter - double the expected 2011 revenue, management indicates. Revenue guidance for 2011 is between $31.5 billion and $33 billion with operating margins between 8.5% and 9%. The stock trades at 17 times its estimated 2011 earnings.