Sorkins is a directory service that specializes in providing detailed information on companies and their executives. It doesn't matter whether the company is public or private, and the dircetory contains listings for local companies and subsidiaries of major corporations as well.
The descriptions are detailed and list full company histories, as well as technical information. You can use Sorkins to find out who's in charge of major divisions of a business, like sales, marketing, PR, IT or advertising. And the service is set up to allow you to perform searches for specific pieces of information.