You bring up an interesting issue. My guess would be that it is against the rules of the contract for non-members to use the discount rate.

For example, the company I work for gets a xx% discount from American Airlines and I know it is against the rules for non-employees to use the discount except if the non-employees are travelling with the employee.

There are certain discount numbers offered pubiclly by Car/Hotel companies -- I see no problem sharing them.

In terms of forming our own "discount group", the airlines would probably require a centralized booking facility in order to track the beneficiaries of the discount and measure its success. The hotels and car rental companies may be a bit more lenient.

--Jim