More people are hopping aboard the Twitter bandwagon, according to new data out today by Pew Internet.

In its Twitter Update 2011 report, Pew Internet found that 13 percent of online adults now use Twitter, compared with just 8 percent of those polled for a similar study last November.

Among those on Twitter, 95 percent own a cell phone, and half of them access the site via their mobile device, noted Pew.

Drilling down the results further, Pew found that Twitter usage has about doubled for most age groups. Among those 25 to 34, Twitter use grew to 19 percent in May from 9 percent last November. Tweeters in the 35 to 44 age group increased to 14 percent from 8 percent over the same period. And looking at a wider age bracket, the number of people 30 to 49 who hopped onto Twitter jumped to 14 percent in May from 7 percent in November.

Looking at the results by race, African-American and Latino Internet users tend use Twitter more than do white users, a disparity that's grown since last year. In the November survey, 13 percent of online African-Americans polled were Twitter users, compared with 5 percent of whites. In the new survey, 25 percent of African-American Internet users were adopters of Twitter, versus 8 percent for white users.

Pew's data was based on a series of telephone interviews of 2,277 adults conducted by Princeton Survey Research Associates from April 26 to May 22.