Results of the third annual Public Radio Technology Survey measured dramatic growth in smartphone adoption among public radio listeners and their clear preference for Apple’s iPhone among mobile hand-held devices. More than a third of respondents now own a smartphone, a 29 percent gain since last year’s survey; within this subgroup of survey participants, 63 percent use the iPhone. The survey of 21,000 public radio listeners, conducted through a partnership of Jacobs Media and Public Radio Program Directors, also shows impressive gains in the number of respondents who listen to public radio via Internet streams. An infographic from Jacobs media sums up the 2010 survey findings; PRPD details top-line results here. For the last survey, released in Sept. 2009, researchers found dramatic growth in the number of respondents who frequented social networking sites such as Facebook.