CorpKnowPedia is an interesting wiki that attempts to monitor the corporate landscape. See, for instance:

* Lists_of_companies
* Master_list_of_corporations

Their purpose as stated on the home page:

"The end goal is to expose the traditionally covert and behind the scenes operations of corporations that increasingly control the world's resources. In order to exercise control over such entities, consumers must recognize the power of their consumptive dollar."