More people in the U.S. are turning to Twitter to satiate their social-media needs. That's according to a new report out today from the Pew Research Center, which says 18 percent of adult internet users in the U.S. are on Twitter, more than double the percentage in 2010.

Not surprising, people aged 18 to 29 are the most likely to use Twitter, with 30 percent of internet users in that age group saying they use the popular social network, the report says.

While 18 percent of internet users may sound low, it's been reported that there are more than 140 million Twitter accounts registered in the U.S. Facebook, meanwhile, has more than 167 million users in the U.S. Of course, these numbers don't account for brands and people who have multiple accounts.

Related: Twitter Updates Web and Mobile Search, Messaging Features

In general, the number of internet users in the U.S. who are on social-media sites is on the rise, according to Pew. Almost three quarters (72 percent) of online U.S. adults use social-networking sites, up from 67 percent in late 2012.

For the report, data was collected from a sample of 2,252 adults, age 18 and older, between April 17 and May 19. The report was produced in association with the Pew Research Center's Internet & American Life Project.

One more interesting finding: While older Americans are still the least likely to use social-media sites, adoption rates for those 65 and older have tripled from 13 percent in 2009 to 43 percent today. So, if your business markets to customers aged 65 and older, you might consider giving Facebook and Twitter a try.

Related: If Twitter Goes Public, Would You Invest?