Smartphones are mobile phones that have additional computer-like functionality, allowing users to perform tasks beyond making phone calls such as emailing and editing documents. Surveys found that 31% of US mobile users owned a smartphone in 2010, rising to an expected majority by the end of 2011. Smartphones accounted for 19% of the 1.6 billion mobile phones sold globally in 2010. They offer benefits like organization, flexible working, and constant access to information, but also have disadvantages such as being expensive and potentially complicated to use.