Under .US Nexus Requirements .US domains may be registered only by the following qualified entities:

* Any United States citizen or resident,
* Any United States entity, such as organizations or corporations,
* Any foreign entity or organization with a bona fide presence in the United States

If you don't live in America, the only legal way you can register .US domains is to establish a "significant" business presence inside the US. One way would be to set up a US corporation which would hold the domains.

You can set up a legitimate US LLC or corporation for anywhere from $100 to $500. I'm not endorsing this service, but here is a sample list of costs depending on the state of incorporation.

http://www.bizfilings.com/products/statefees.asp

Generally Delaware and Nevada are the top choice as states that are most favorable for low or no corporate income taxes.