Fortune rank: 16
2008 profit: $6.41 BillionVerizon's wireless business, its biggest growth engine, helped grow profits 16%. More than six million new customers joined the country's No. 1 wireless carrier, lured in by deals like 2-for-1 Blackberrys.
Data sharing on its 3G network also boosted gains: In the fourth quarter, Verizon customers sent or received 90 billion text messages - double the number a year ago.