W.L. Gore and Associates (http://en.wikipedia.org/wiki/WL_Gore_and_Associates) is a big company that appears to try hard to avoid hierarchical structures. From a 2004 FastCompany article (http://www.fastcompany.com/magazine/89/open_gore.html):

"So Bill Gore threw out the rules. He created a place with hardly any hierarchy and few ranks and titles. He insisted on direct, one-on-one communication; anyone in the company could speak to anyone else. In essence, he organized the company as though it were a bunch of small task forces. To promote this idea, he limited the size of teams -- keeping even the manufacturing facilities to 150 to 200 people at most. That's small enough so that people can get to know one another and what everyone is working on, and who has the skills and knowledge they might tap to get something accomplished -- whether it's creating an innovative product or handling the everyday challenges of running a business."

Anyone who works for Gore care to comment on the actual practice?