(Clint Boulton, eWeek) Nielsen's survey of 200,000 mobile Web users from June 2009 to June 2010 indicated that e-mail use devoured 41.6% of mobile Web users' time. That's a lot of messaging on Apple's iPhone, Google's Android devices and RIM's BlackBerry smartphones.

Social networking on Facebook, Twitter and other Websites may dominate on the desktop, but time spent consuming e-mail rules the roost on mobile devices in the United States, according to Nielsen. This Nielsen clock/pie chart shows how mobile Web users spend an hour on their mobile devices, such as BlackBerry devices, Apple's iPhone or smartphones based on Google's Android operating system.

Note that users spent on average 25 minutes in an hour using e-mail, or three and one-half times as much as the 7 minutes the average respondent spent on Web portals such as Yahoo or MSN. Social networks such as Facebook and Twitter consumed 6 minutes of the average mobile Web user's time.