According to a new report by the Pew Internet & American Life Project studying the use of Twitter and social media services that allow status updates, 11 percent of U.S. adults update their status online.

Twitter is the most popular and best known of the dedicated status update sites. Facebook is a much larger network that added a status update feature last year. Many reports on the Internet are stating that 11 percent of U.S. adults have used Twitter. That appears to be incorrect as the report looks at Twitter and similar services.

The most interesting findings:

• The median age of a Twitter user is 31, older than the median age of a Facebook or MySpace user
• Twitter users are more racially and ethnically diverse than the full U.S. population, because the average Twitter user is younger than the average American
• Twitter users are more likely to live in an urban area. 35 percent of Twitter users live in one, while 29 percent of Internet users live in an urban area
• Nearly one in five (19 percent) online adults ages 18 and 24 have ever used Twitter and similar services
• 20% of online adults ages 25 to 34 have used Twitter and similar services 
• Use drops off after that age bracket sharply. 10 percent of those ages 35 to 44 year olds have used microblogging services
• 5% of 45 to 54 year-olds have used microblogging services
• Just 4% of 55-64 year-olds and 2% of those 65 and older use Twitter.

Pew concludes:

“In conclusion, Twitter users engage with news and own technology at the same rates as other internet users, but the ways in which they use the technology – to communicate, gather and share information – reveals their affinity for mobile, untethered and social opportunities for interaction. Moreover, Twitter as an application allows for and enhances these opportunities, so it is not so surprising that users would engage in these kinds of activities and also be drawn to an online application that expands those opportunities.”