When it comes to being in vogue in Britain, barter is, as they say, the new black.

Rising inflation, a credit squeeze, crumbling stock markets and a slowing economy with job losses have prompted an explosion of cyber markets where consumers can get what they want without spending any of their precious and dwindling cash.

Swap shops for everything from clothes to books to toys and games are springing up all over the Internet, and some have developed their own virtual currencies.

"Our business is going up and up," said Jonathan Attwood, director of the SwapitShop.com barter website for young people. "Last month alone we had more than 40,000 new subscribers, and our members are now trading more than a quarter of a million of pounds worth of goods every month."

Attwood reckons some $10.35 billion are tied up in unused games, music and toys lying around in kids' bedrooms, and through barter sites like his, "savvy kids are unlocking one of Britain's biggest hidden resources."

Adults too, with an estimated 2.4 billion unworn items hanging in wardrobes across Britain, are getting wise to the cyber bartering.

As food and fuel price inflation takes ever larger chunks out of tightening family budgets, bartering has swiftly turned from an idea prompted by a desire to be environmentally aware or join the vintage fashion trend, into a basic necessity.

Attwood, whose site has its own currency "swapits", says a simple shortage of cash is driving his business.

When times are hard, he says, people feel good about using something old to get something new, and with barter there is no guilt about reckless spending.

"Kids are natural traders anyway, and now they are getting less pocket money and their parents are less willing to buy things for them," he said. "Swapping is the natural solution."

Andrew Bathgate, who launched ReadItSwapIt.com for book lovers to trade old for new for nothing, tells a similar tale.

Barely three months ago, his site was seeing steady business of around 7,000 book swap requests a month. That number has now shot up 15,000 a month, with a cash-free book swap taking place every three minutes.

"Books can be an expensive hobby ... and at times of cost cutting people may not have the spare cash."

The bartering business is also spreading beyond physical commodities into services and specialist trades.

On the Barter Swap UK website, Fiona, a qualified teacher in Devon, southwest England, is offering tutoring for children up to age 11 in return for someone to lay wooden flooring in her conservatory, while Catherine, also in Devon, is offering the use of a holiday home in Austria to anyone who will transport her furniture there.