1. A method for cross-trading commodities and the like among a plurality of exchanges comprising: providing a computer; establishing a communications link between the computer and the Internet; providing a database, accessible by the computer, containing a plurality of user files wherein each of the plurality of user files corresponds to a specified user of the system and further containing levels of permission to access and/or trade corresponding to a plurality of exchanges to which the specified user may access; providing a database, accessible by the computer, containing a plurality of open offers and bids wherein each of the plurality of open offers and bids contains information corresponding to open bids or offers for commodities and the open offers and bids are organized according to the commodities to which they correspond; providing at least one computer site for transacting specified commodities executing on the computer accessible by selected users having proper levels of permission to access and/or trade for each exchange; and presenting open offers and bids from more than one exchange transmitted from the computer to a user of the system over the communications link, querying the user database to retrieve levels of permission to access and/or trade from a user file corresponding to the user, retrieving open offers and bids from the indication database corresponding to the user, retrieving open offers and bids from the indication database corresponding to the predetermined commodities within the exchanges to which the user has been determined to have access, generating a presentation of the retrieved open offers and bids having commodities from more than one exchange displayed thereon, and transmitting the presentation to the user over the communications link.