We research the political impact of how users access the Internet. Recent research suggests that Internet usage may promote political participation. Internet usage is proposed to be beneficial because it increases activity in diverse politicized social networks and through greater access to information. Even though Internet usage may begin as a non-political activity, we outline several reasons to believe that it may spark later political participation. This impact, however, is likely to be non-existent in new forms of Internet browsing such (...) as through mobile phones, where users do less full-scale browsing. The more difficult browsing interface of mobile phones reduces activity in chat rooms and in-depth browsing of online sources of information which promote participation. To test these ideas, we use nationally representative survey data from Japan, a country which has more pronounced usage of mobile phone browsing. Using a Seemingly Unrelated Regression Model, we also show that the chief determinants of using PC's over mobile phones for Internet browsing are age and education. We then show that PC-based Internet activity correlates with increased political participation, but mobile phone usage correlates with less participation. (shrink)