Phone calls and letter writing are things of the past, and social networking, blogging, and text messages are now the dominant forms of communication for adults aged 18 to 34, according to a new study by Interpublic's Universal McCann unit.

The study found that 85 percent of U.S. adults in that age group rely on one or more Web 2.0 platforms to stay in touch with their friends and family, and the numbers have grown steadily year over year.

The percentage of adults who rely on instant messaging to communicate rose to 22 percent this year, up from 9 percent in 2007. Among 18- to 34-year-olds, 21 percent rely on IMs, compared to 14 percent last year.

The blogging craze is showing no sign of slowing down either. One out of every 10 U.S. adults publishes a blog, which is double the amount who blogged in 2007. Meanwhile, one out of every five 18- to 34-year-olds has a blog, up from 10 percent a year ago.

Although consumers are dissatisfied with the mobile internet, that isn’t stopping them from using their mobile devices to send text messages. In 2007, nearly half of U.S. adults said they had never sent a text. This year, that number is down to 41 percent.