Even if your product is patented, trademarked, and protected to the hilt in the U.S., you might not have any protection at all once you start selling overseas. In many cases, you'll have to file for protection in every country in which you're doing business. Not that it's hopeless: In November, the U.S. joined the Madrid Protocol, which allows you to file for trademark protection in 60 countries simultaneously.
The Patent Cooperation Treaty, signed by about 120 countries, should also help. If you file for protection under the treaty within a year of filing in the U.S., you'll get 18 more months to file in any of the other signatory countries, even if you're already selling there.
There are two important ways in which the process of getting a patent is different overseas. In the U.S., if two people ask for a patent for the same idea, the one who is approved first gets the patent. In most other countries, the person who files first gets the patent. Also, most other countries don't let you get a patent if you first start selling your product without one (in the U.S., there's a one-year grace period).
David W. deMartino, CEO of Ozonelite, is trying to protect his invention even as word about it spreads. His eight-employee Deerfield Beach (Fla.) company, which was founded in 2003, sells a lightbulb that kills germs and odors. He filed for a U.S. trademark registration that year, not expecting to expand overseas soon. Then, thanks to a magazine article, word about the product spread -- to Portugal, Spain, Greece, Australia, Korea, and Hong Kong. DeMartino quickly filed for protection internationally and fended off inquiries until the approvals came through in January. "It's tempting to go after these markets," deMartino says, but "I feel I can't do business globally until I have the right protection."