From the well-sourced rumor file: Facebook, which began allowing employees from a handful of companies to become members last week, may be adding another 1,000 companies on Tuesday.

Facebook determines if a person is a member of a college, high school or corporate network based on their email address. As they add companies, anyone with an email address from that company can become a member of that company’s network on Facebook.

Here’s something I’d love to have: a TechCrunch Facebook network. I would issue email addresses to TechCrunch readers and we could have a private network of people who want to discuss new startups and share information about themselves. I don’t think this is in Facebook’s plans, but I’d enjoy doing it.