A lot of analyst reports are churned out once the quarterly earnings season ends, but ABI Research's quarterly handset roundup is one to take note of. ABI's Michael Morgan checks out the world's 10 largest branded cell phone makers in the first quarter of 2011, providing sales data as well as insight into their strategy and competitive position in the market. Though most research firms only list the market's top five handset makers, ABI lists the full top 10 (and the firm is providing shipment numbers for all of the vendors listed). Which companies are sinking and which are on the rise? Special report