Online traffic to YouTube and other online video sites doubled last year compared with 2006, as almost half of adult online users say they visited such sites, according to a research report released Wednesday.

According to a national phone survey done by the Pew Internet & American Life Project, 48% of more than 1,300 Internet users surveyed between October and December 2007 said they visited a video-sharing site like YouTube during 2007. A survey in December 2006 found that 33% of Internet users said they had visited such sites last year, Pew said.

Pew said that 15% of participants in the latest survey said that they had used a video-sharing site the day before they were contacted. A year ago, only 8% of users said they had visited such a site the day before. The research concluded that on an average day, the number of users accessing video sites last year almost doubled from the end of 2006.

The site said the growth can be traced to increased use of such sites by men, adults under 30 and college students, the study noted. Almost one third (30%) of wired young adults watch a video on a site like YouTube on a typical day, while a fifth of all online men do the same, the report said.

In addition, average daily traffic to video sites increased by 120% among women, by 100% among people between 30 and 49 and 160% among high school graduates.

The traffic increases mirror the spread of broadband connections. The 2007 Pew survey found that 54% of all American adults have broadband at home, up from 45% a year earlier.

The report noted that the increased popularity of such sites can also be traced to a rapidly increasing number of videos posted. The survey found that 22% of Americans shoot their own videos and that 14% of them post some of that video online.

That is more than triple the percentage of users who said they had posted homemade videos in the 2006 Pew survey.