By Matthew Wells
BBC News, New York
Heyday, a new membership organisation for those approaching or in retirement, has launched in the UK with the backing of Age Concern.
Similar groups already operate in the US, including the American Association of Retired Persons (AARP), which has a strong social and political voice in the country.
The US organisation has more than 36 million members
The AARP is arguably the most powerful non-governmental group in the US, representing more than 36 million people.
With such a huge number of members, who pay the modest annual sum of $12.50 (£6.73) per household, it is inevitable that some who pay their dues feel hard done-by when the organisation takes a clear stand, such as backing the huge prescription drugs bill which was passed a few months ago.
"It's a non-partisan, not-for-profit, membership-based organisation that is serving the needs and interests of persons aged 50 and over," said Ladan Manteghi, president of the AARP's global network.
"We exist for the purposes of delivering social change, that is the key point.
"The clout of our membership has the capacity to influence and bring about social change through government policies, through society, as well as through the marketplace."
It's a lofty ideal, but the lobbying power of the AARP in undeniable, as is its ability to alter the perception of ageing across America.
Only the Catholic Church has more members and the main magazine is distributed to 22 million households, making it the largest circulation publication in the country.
This month Sir Paul McCartney is on the cover, and it also broke news in an interview with former US Secretary of State Colin Powell in which he talked frankly about Iraq and the decisions made before the war.
The point, perhaps, is that neither man is exactly past-it, and the AARP was once known as an organisation primarily for the white, affluent and rightward-leaning, but things are different now, said Tony Sarmiento, of Senior Service America Inc.
"They've made a major effort to come to grips with the increasing diversity of the ageing population," said the Filipino-American executive director, whose federally-funded organisation focuses on job opportunities for the over-55s.
"The AARP does a tremendous amount of research on the ageing of society, and makes information and images of ageing much more visible to all Americans," he added.
In recent years, the AARP has come under attack from both sides of the political spectrum.
Currently it's been incurring the wrath of the Right for opposing the president's now stalled attempts at social security reform.
But some critics are more concerned about the way that it makes money through its services arm, with plenty of mail-shots offering all manner of services and discounts.
"I found it was really a Fortune 500 company that sidelines as a lobbying organisation for the Washington staff," said journalist Dale Van Atta, author of the book "Trust Betrayed: Inside the AARP", in a recent television interview.
He believes the organisation is run by a liberal, money-grabbing elite which does not serve its membership well.
The AARP magazine broke news in an interview with Colin Powell
Ms Manteghi insists that AARP is as representative as it can possibly be.
"We have the ability to negotiate better deals for our members, and better deals doesn't always mean the cheapest product on the market... it's about filling market gaps.
"We, through the clout of our membership, are able to negotiate... to develop a product that we specify, not that the market dictates."
The AARP is proud of its bargaining power and the way that it can focus all its efforts on fighting one big battle if necessary - such as over social security reform.
Its website is a formidable information platform, where members can also visit an array of message boards, under categories like "Grief and Loss" and "Health and Wellness".
The view from one White House official quoted anonymously in a recent magazine article, that the AARP is an "ossified bureaucracy" and "unresponsive" to its membership, is clearly not an objective one, and Ms Manteghi is glad that Heyday is being launched in Britain this week.
"Now is definitely the time, and we congratulate Age Concern for seeing the opportunity and for creating an entity that will finally provide strength and voice for the UK's 50-plus population," she said.