The driving force behind the growth has been the addition of clients that make mobile access easier.
"We quickly understood that we were doing users a disservice by not having a great client on each of the major mobile platforms," said Twitter's CEO, Evan Williams. "So, we took a similar approach with Twitter for BlackBerry and Twitter for Android."
Twitter's mobile site, mobile.twitter.com, was used by 14 percent of users and Twitter's SMS option was used by eight percent of users. Twitter iPhone apps represented eight percent of usage and the BlackBerry app represented seven percent of usage.