20% of tweets are from mobile devices, claims study

But Rapleaf's research finds that Twitter's website is still the most popular way to post.

Social media firm Rapleaf has released the results of a study of tweets from more than four million Twitter users, which sought to find out how they were accessing the micro-blogging service.

The company claims that roughly 20% of all tweets are sent from mobile devices - phones and PDAs. That includes 6% sent by text message, 4% using Twitter's mobile site, 3% from iPhone app TwitterFon, and 2% from BlackBerry client TwitterBerry.

Texting is actually the second most popular way to tweet, although it's a long way behind the 65% of tweets posted using the main Twitter website.

"With 65% of all tweets sent from computers on the official twitter site and about 20% of tweets sent from mobile devices, there's still a lot of room for Twitter to expand into the growing mobile sector," says Rapleaf's blog post announcing the results.

"Whether this will affect the proportion of active Twitter users remains to be seen."