A website to help parents complain about what campaigners have dubbed the "pornification" of children should be put in place within months, David Cameron said.
The measure is among the recommendations of a Government-commissioned review of the sexualisation and commercialisation of young people carried out by Mothers' Union chief executive Reg Bailey.
Mr Cameron also backed moves to make it easier to block adult content on mobile phones, ban raunchy billboard posters near schools and bar the use of youngsters to market products.
And he said he would summon retailers, advertisers, broadcasters, magazine editors, video games and music industry chiefs and regulators for a summit in October to discuss progress.
Under the changes proposed by Mr Bailey, steamy pop videos would be restricted to older teens and later television slots and magazines featuring sexualised images covered up on shelves.
An option to request adult material be barred from any new home internet service, laptop or mobile phone should also be introduced and parents given more say in the TV watershed guidelines.
Mr Bailey said he hoped his review would help tear down the sexual "wallpaper" surrounding today's young people and give parents a stronger voice in regulation.
Welcoming the report, Mr Cameron told him in a letter that it represented "a giant step forward for protecting childhood and making Britain more family-friendly".
While ministers would examine the recommendations, most required action from business and regulators who would have to be held to account "in a transparent way", he said.
Ministers were keen to stress that it was not a question of state interference.
Mr Cameron said he was particularly keen to see rapid progress on a centralised online tool for parents to report inappropriate material or products.
"This not only seems entirely sensible, but also relatively easy and simple to introduce.
"I see no reason why the website cannot be up and running in good time to get feedback from parents for our October meeting," he said.
The six-month review took evidence from more than 2,000 parents and 500 young people as well as 120 separate organisations.
Mr Bailey said: "Regulators, businesses and broadcasters should do more to connect with parents - it's not enough for them to work out what is acceptable from what people complain about afterwards.
"I hope that they see that it's good business if you look out for families. Then we can all help to make Britain a more family friendly place."
The Advertising Standards Authority and communications regulator Ofcom said they were determined to ensure parents had a sufficiently powerful voice.
The Bailey report said the new website was needed to help parents cope with the large number of different regulators with responsibility in the area.
It should "set out simply and clearly what parents can do if they feel a programme, advertisement, product or service is inappropriate for their children, explain the legislation in simple terms provide links to quick and easy complaints forms on regulators' own individual websites".
A forum allowing anonymous comments could also act as an extra gauge of opinion it suggested, and the responses of regulators to complaints published regularly.
In response to demands for restrictions on inappropriate children's clothing - including lace lingerie and push-up bras - the British Retail Consortium has also launched new guidelines.
Nine stores - Asda, Debenhams, Argos, John Lewis, Next, Marks & Spencer, Peacocks, Sainsbury's and Tesco - have signed up with others being urged to participate.
Justine Roberts, who co-founded the Mumsnet website, welcomed the review and new guidelines for retailers.
"This is not about prudishness or hankering after some rose-tinted picture of childhood," she said.
"It's about millions of parents - and many who aren't parents - knowing in their bones that there is something wrong with a society that tries to sell seven-year-old girls four-inch heels, or t-shirts emblazoned with 'Future Porn Star.
"As parents we're told - often by our own kids - that we've just got to live with it, that the world has changed.
"But we don't have to and our Let Girls be Girls campaign, the Bailey review and the new retail code of conduct show the power ordinary people can wield when they speak out forcefully on forums like Mumsnet against the pornification of our culture."
The retail guidelines advise stores that "fabrics and cut should provide for modesty" while skirt length and neckline "need careful consideration" and underwear ranges need "the utmost care in design".Reuse content