The Consumers' Association, publishers of Which? magazine, are setting up an Internet site called Which? Online to be launched in the Autumn offering a range of products.
If, for example, someone wants to buy a particular make of car they will be able to get together with other potential buyers to exchange information to discover the cheapest dealer and make a joint approach to himto get the best price.
Users will also be able to exchange information about faults or problems with appliances.
"So if you are living in Grimsby and you need a plumber you will be able to go online and find out from other members in the area who will give you good and cheap service," said Paul Kitchen, Which? Online's managing editor.
Electronic trading has been available on the Internet for some time but aimed at companies which want to buy or sell industrial goods.
But individuals have been wary of the practical and legal problems of dealing with strangers. The Consumers' Association hopes that its image as the champion of consumer rights will overcome this fear.
The association is also planning its own credit card with its name and logo displayed, in the hope that retailers will be encouraged to give good service.
Of its 750,000 members, the association expects 50,000 to be able to go online. It is hoping to attract new members in the 25-35 age group.
The association will also put online its vast library of reports on consumer goods and services including household appliances, holidays, cars and financial services.
"Consumers will no longer be passive receivers of information," said Mr Kitchen. "They will be able to use it to get in touch with experts and interact with other consumers."