Americans spend much of their time online visiting social network sites and blogs when they are in front of a full sized screen, but on mobile devices their activities are very different. A Nielsen study released this month, "Wha

t Americans Do Online: Social Media and Games Dominate Activity," breaks down US online time on personal computers and wireless devices.

Social networks took up 22.7 percent of online Internet time in June 2010, an increase of 43 percent from June 2009. Online games increased ten percent from last year to 10.2 percent of total time - playing games online overtook personal e-mail as the second most used activity this year. E-mail's share was 8.3 percent, down 28 percent from last year. Other activities, such as visiting portals, instant messaging and other categories, decreased in usage. Watching video or movies, as well as conducting searches, were the only other categories that increased from last year.

But on mobile devices, US consumers spend much more time on e-mail than any other activity. While mobile Web users increased their social networking behavior on mobile 28 percent, e-mail rose from 37.4 percent last year to 41.6 percent. Second in heaviest activity was portals at 11.7 percent, and mobile music and video consuming rose twenty percent. Social networking only took 10.5 percent.

To illustrate the proportions of Internet usage, Nielsen organized the categories around a stopwatch. If all mobile Internet time was condensed into one hour, each category took up a certain number of minutes and seconds.

e-mail- 25 minutes
portals - seven minutes
social networks and blogs - six minutes and eighteen seconds
Search - four minutes and twelve seconds
news - two minutes and 42 seconds
entertainment - two minutes
music - one minute and 54 seconds
weather - one minute and 42 seconds
sports - one minute and 24 seconds
time spent on video- and movie-specific sites (YouTube, Hulu, etc) or movie-related Web sites (IMDB, Netflix, etc) - one minute and twelve seconds
other remaining online sectors - six minutes and 42 seconds