Shawn Fanning (left), founder of file-sharing service Napster, listens as his attorney David Boies (second from right) addresses a press conference regarding the company's copyright infringement woes in October 2000.

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Patent attorneys (also known as patent agents) help companies, universities and individual inventors protect their intellectual property rights. Intellectual property is any original creative idea in the form of manufactured items, machines, processes or chemical compounds [source: Dillon]. A patent is a form of legal protection issued by the U.S. Patent and Trademark Office, part of the U.S. Department of Commerce.

Patents differ from trademarks -- words, names or symbols used to identify the source of a product or service -- and copyright, which protects "original works of authorship" like movies, songs, books and plays [source: USPTO].

Anyone can apply for a patent, but that doesn't mean that everyone should. The patent application process is very complex. To get an idea of what the process entails, read a few of the patent applications on the Google Patent Search. A successful patent application must not only describe the invention in great detail, but explain exactly what this invention would exclude other people from doing without permission of the patent holder [source: Dillon]. If you think you have a truly original, useful idea for a product or service -- particularly if that idea is technologically complex -- you should definitely contact a patent attorney.

Patent attorneys perform two important legal services: prosecution and litigation. Prosecution is their name for the patent application process, and litigation refers to the enforcement of existing patents through patent infringement cases [source: Herman]. You should also contact a patent attorney if you want to license your patent to another company or individual. Patent attorneys know the specialized contracts and terms of licensing agreements well. If someone accuses you of infringing upon their patent or using it without a license, you should contact a patent attorney to defend you.

A regular attorney can't fill in for a patent attorney. Patent attorneys are licensed to practice before the U.S. Patent and Trademark Office (USPTO). They typically hold undergraduate or graduate degrees in engineering. This helps when determining if your invention constitutes an original, useful idea in your specific technical field or industry. Patent attorneys are also required to pass a second state bar exam -- called the patent bar -- before they can practice [source: Herman].

Before you contact a patent attorney, do a simple search to make sure that no one else has already patented your idea. The U.S. Patent and Trademark Office (USPTO) has a searchable online database for both existing patents and pending patent applications.

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