I'm building a site that includes a business directory. Here are a couple issues that come to mind:
Each user can belong to one or more company. Likewise, a company can have many users linked to it.
You'd need to avoid the creation of multiple profiles for the same company. You also want to grant only certain users permission to edit a company profile.
I'm thinking I need to create a "Company Profile" content type. As a minimum, I'd be happy to give users the ability to select their company and then show a link (or links) on the user profile page to companies they are associated with.