Twitter is now being used by 8 percent of online adults in the United States, according to a report out today from Pew Internet.

Based on survey results, the study found that among the Twitter users interviewed, 24 percent check their tweets several times a day, while 12 percent check in once a day.

Breaking down the demographics, adults ages 18-29 are much more likely to use Twitter than are older adults, minority users (African-Americans and Latinos) are twice as likely to use the service as are white users, and city dwellers are twice as likely to hop onto Twitter as are rural residents.

Looking at the people who like to tweet, Pew found that 72 percent of them post updates about their personal lives or interests, 62 percent post updates about their work lives, 55 percent share links to news stories, and 53 percent retweet items tweeted by other people.

This latest survey from Pew follows several other polls conducted between August 2008 and September 2010 in which the results were misinterpreted by several analysts and readers, according to the research firm. For the August poll, 6 percent of Internet users said they used Twitter or a similar service, while in September, 24 percent said the same thing. But some people thought those numbers represented just Twitter users when they actually covered other social networking sites, such as Facebook and MySpace.

To clear up that misconception and to focus strictly on Twitter, Pew framed the question in its new survey as simply: "Do you use Twitter"

The results were compiled by Pew from a November tracking survey that reached around 2,250 people. But two omnibus surveys run in October asking the same question also found around 8 percent of those polled use Twitter.