The "networked generation" is driving a radical shift in media consumption, says UK telecoms regulator Ofcom.
Young adults are moving away from traditional media
Sixteen to 24 year olds are spurning television, radio and newspapers in favour of online services, says the regulator's study.
The 2006 Ofcom report also found that increasingly households are turning to broadband and digital TV.
And it notes 1.8 million homes are now using their broadband connections for internet telephone calls.
The Ofcom report analysed industry and consumer trends in television, radio and telecommunications during 2005-6.
It discovered young adults, whom it has dubbed the "networked generation", are embracing new technologies much more quickly than the general population.
Sixteen to 24 year olds, it reports, spend nearly three hours on the net each week.
Seventy percent (compared to 41% of the general population) have used some kind of social networking site, such as My Space, and one in five have their own website or blog. Half of the group owns a games console and/or an MP3 player.
Ofcom's research suggests this online lifestyle may have contributed to a fall in television viewing - this age group watch seven hours less television per week than the average viewer.
But when they do watch TV, it found they are turning away from public service broadcasting in favour of digital channels.
The reduced consumption of other media, such as newspapers, magazines and radio, amongst this age-group compared to the general population, has also thought to have been driven by the net.
A spokesman for Ofcom said: "The speed at which consumption habits for this age group is changing is faster than other groups.
"They are leaving the traditional media and moving towards new media.
"This generation has grown up with new technologies - and it is this generation for whom the uptake is instinctive."
Kay Withers, a research fellow at the Institute of Public Policy Research (IPPR), said: "There have been lots of studies showing the younger generation are shifting away from traditional to new media, but at IPPR we are seeking to understand why this is and what this means.
"We want to find out what it means to turn away from newspapers and public service broadcasting, and to find out the types of news sources they are now favouring.
"This could have a major impact on media regulation, public policy and on the political world too."
The report also found technology adoption is not limited to the young.
From 2004 to 2005, the number of households with broadband connections increased by 63%, while a total of 18.3m homes now have digital television.
Ofcom also said that a number of "converged services" had arrived on the market, such as internet telephony, internet television offerings and television to mobile content.
Mobile phones are also playing an increasingly important role; Ofcom found as many households had a mobile phone as had a landline.
But despite increased consumption, the average household spend on telecoms fell by 5% to £76 a month between 2004 and 2005.
Ofcom chief operating officer Ed Richards said: "Our research reveals dramatic and accelerating changes across all communications industries.
"The sector is being transformed by greater competition, falling prices and the erosion of traditional revenues and audiences."