71% of Twitter Users Tweet from a Mobile Device

Between March 2012 and October 2012, the proportion of people who used a desktop or notebook computer for tweeting fell from 77 percent to 64 percent. 

The percentage who used a mobile phone for tweeting rose from 53 percent to 64 percent, and those using a tablet rose from 9 percent to 18 percent. 

Overall, the proportion of Twitter users using a mobile device (either tablet or phone) rose from 56 percent to 71 percent.