Interesting article:

Special Report: A little house of secrets on the Great Plains | Reuters

CHEYENNE/ATLANTA (Reuters) - The secretive business havens of Cyprus and the Cayman Islands face a potent rival: Cheyenne, Wyoming.

At a single address in this sleepy city of 60,000 people, more than 2,000 companies are registered. The building, 2710 Thomes Avenue, isn't a shimmering skyscraper filled with A-list corporations. It's a 1,700-square-foot brick house with a manicured lawn, a few blocks from the State Capitol.
Wyoming Corporate Services will help clients create a company, and more: set up a bank account for it; add a lawyer as a corporate director to invoke attorney-client privilege; even appoint stand-in directors and officers as high as CEO. Among its offerings is a variety of shell known as a "shelf" company, which comes with years of regulatory filings behind it, lending a greater feeling of solidity.

"A corporation is a legal person created by state statute that can be used as a fall guy, a servant, a good friend or a decoy," the company's website boasts. "A person you control... yet cannot be held accountable for its actions. Imagine the possibilities!"
"In the U.S., (business incorporation) is completely unregulated," says Jason Sharman, a professor at Griffith University in Nathan, Australia, who is preparing a study for the World Bank on corporate formation worldwide. "Somalia has slightly higher standards than Wyoming and Nevada."