The E-2 Investor Visa allows an individual to enter and work inside of the United States based on an investment he or she will be controlling, while inside the United States. This visa must generally be renewed every five years, but there is no limit to how many times one can renew. The investment must be "substantial". Investor visas are available only to treaty countries,[1] which include countries like Albania and Senegal, but do not include Brazil, Russia, India and China.[2]

http://en.wikipedia.org/wiki/E-2_visa

Just did a quick search for Canadians, so it might be different for other countries, as stated above.