Admob who tracks internet connections from mobile phones (and now from mp3 players) published their report on December 2008. They noted an explosion of the presence of the iPod Touch on the web whose volume was multiplied by 3,4 in one month (only 2,9x in France).
The iPhone also goes very well and now accounts for 32% of the smartphones on the Web on a world level and 48% for the United States, these are figures that do not take the iPod Touch into account.
[translation by crispin]
