Now there is a Nineties version of the coffee houses that proved to be the genesis of the London stock exchange in the 17th century.
They are called bulletin boards and these on-line investment discussion groups have both the industry regulators and publicly quoted companies worried.
The regulators are concerned that this new wave of Internet-inspired private investors, who have rushed headlong into share-dealing, are being unduly influenced by the often unreliable information posted on these sites.
They say that the information is at best of dubious quality and at worst provided by people who are only interested in ramping shares they have already bought.
Publicly quoted companies are worried because these on-line chatrooms have opened up a hornets nest of gossip, deliberate dis-information and mischief-making over which they have precious little control.
Traditional press offices, long used to dealing only with more traditional media outlets, find themselves embroiled in a world that they barely understand but which can cause huge gyrations in the share price of the companies that they represent.
The only people who do not appear to be worried by it all are the users, who suddenly find themselves able to swap news and views about investment tips in a way that was previously impossible. They can say what they like, when they like and there is precious little that the regulators can do to stop them.
"It's like the Wild West," says one stockbroker. "People say all kinds of things and it is very difficult to distinguish between the quality tips and the rubbish."
There are a host of bulletin boards, with the best known including the Motley Fool site, E*Trade and Hemmington Scott. Most of them supply regular investment news but also offer links to bulletin boards where members can e-mail in their comments.
Some of it can be extremely accurate. Take this from the Motley Fool bulletin board on 24 November: It reads:
"Guess what I heard today?
t Stock: United Biscuits
t Info: Takeover by rival
t Stage of deal: Last few days of due diligence, ie a matter of weeks
t Buyer: This is a surprise ... Danone."
The share price then was around 220p. This week Danone duly emerged as a member of a consortium that is embroiled in a bid battle for United Biscuits that has pushed the shares to 260p. Other so-called "hits" have included tips on bulletin boards that Benckiser, the Dutch household products group was set to bid for Reckitt & Colman, which also proved correct.
Fans of bulletin boards say that they are a great way for smaller investors to steal a march on the institutional investors who have treated this new area with considerable disdain. Critics say that not only is some of the information wrong, but some of the better tips are simply re- hashed stories which have already appeared in stock market reports in established newspapers.
Dialog, the on-line information business is one company that is a regular victim of negative bulletin board gossip. At one point Dialog's share price fell 7 per cent for no apparent reason, until a negative item was traced to a bulletin board.
Another item appeared on the Market Eye board on 30 November. "SkyePharma - set to rocket - I can say no more. Author Can Man" SkyePharma's share price on 1 December was 58p. It has continued to fall with no significant news.
Andy Yates, the head of operations at Digital Look, an organisation that offers a summary of the top tips on bulletin boards says that these on-line investment chat rooms are useful if used carefully. But he warns: "They are dangerous if you believe everything you read. But they can be extremely useful and informative. They are on-line communities with people spreading information and helping each other."
The most talked about companies on Digital Look's site are Marks & Spencer, Freeserve and Pacific Media.
Mr Yates says people who regularly abuse the system get found out and are either ignored or banned by the better boards.
His advice to "newbies", an Internet word for newcomers to bulletin boards, is to initially act as a "lurker".
A lurker is someone who looks at all the comments being posted on a bulletin board but doesn't post anything. This enables a newcomer to become familiarised with how the boards work and learn how to sift the good comments from the wilder rumours before they start to trade on them.
Digital Look's advice is to do your own research, beware of share tips, watch the boards closely and don't be afraid to ask questions. Proshare, the organisation that campaigns for wider share ownership has mixed views about the bulletin board phenomenon.
Jeremy King of Proshare says: "They have a place but come with a warning. There are unscrupulous people out there who use these things for their own ends.
"You have to view these bulletin boards as a starting point of research not as the end point. And never, ever rely on the tips."
The Financial Services Authority points out that it is a criminal offence to deal on information that has deliberately manipulated the share price but admits the Internet will be extremely difficult to police. At the moment these offences are policed by the DTI, though the FSA will take control next year when the Financial Services and Markets Bill becomes law.
A spokesman said: "People need to be aware of the risk. We are saying to consumers that if they are seeking investment advice, they should use an authorised firm."