List of Internet Domain Extensions and What They Mean (Yes, they actually DO mean something!)

• .com represents the word "commercial," and is the most widely used extension in the world. Most businesses prefer a .com domain name because it is a highly recognized symbol for having a business presence on the Internet.
• .net represents the word "network," and is most commonly used by Internet service providers, Web-hosting companies or other businesses that are directly involved in the infrastructure of the Internet. This is why "Dr. Bill Bailey.NET" is called ".NET" since we are a web site hosting service. Additionally, some businesses choose domain names with a .net extension for their intranet Websites. Originally intended for use by domains pointing to a distributed network of computers, or "umbrella" sites that act as the portal to a set of smaller websites.
• .org represents the word "organization," and is primarily used by non-profit groups or trade associations. It is also used by Non-Profit ministries, and is very widely known and accepted.
• .biz is used for small business Web sites.
• .info is for credible resource Web sites and signifies a "resource" web site. It's the most popular extension beyond .com, .net and .org.
• .mobi (short for "mobile") is reserved for Web sites built for easy viewing on mobile devices.
• .us is for American Web sites and is the newest extension. It has the largest amount of available names in inventory.
• .ly is a country site for the nation of Libya, and is used by some because of "spelling" things, like "on.ly" and "bit.ly"
• .cc was originally the country code for Coco's Keeling Islands. It is unrestricted and may be registered by anyone, from any country.
• .bz was originally designated as the country code for Belize, but is now commonly used by small business who can't get the name they want using the .biz extension. It is unrestricted and may be registered by anyone, from any country.
• .tv is the country domain for Tuvalu, a Pacific island nation, and has come to be used mainly for rich content/multi-media Web sites, commonly used within the entertainment or media industry. Thus, our Internet TV Protocol (IPTV) site is: DrBill.TV
• .me is the country code for the nation of Montenegro, and has come to be used for personal (vanity) sites. (As in, it's all about "me.")
• .pro Currently, .pro is reserved for licensed or certified professionals worldwide. A professional seeking to register a .pro domain must provide their registrar with the appropriate credentials.
• .int The .int TLD is strictly limited to organizations, offices, and programs which are endorsed by a treaty between two or more nations. However, there are a few grandfathered domain names that do not meet these criteria.
• .jobs The .jobs TLD is designed to be added after the names of established companies with jobs to advertise. At this time, owners of a "company.jobs" domain are not permitted to post jobs of third party employers.
• .name This is an open TLD; any person or entity is permitted to register; however, registrations may be challenged later if they are not by individuals (or the owners of fictional characters) in accordance with the domain's charter.
• .tel A contact directory housing all types of contact information directly in the Domain Name System.
• .travel Must be verified as a legitimate travel-related entity.
• .vg is the coutry code for the British Virgin Islands. It is unrestricted and may be registred by anyone, from any country.
• .ws was originally designated as the country code for Western Samoa, but is now commonly used as an acronym for "Web sites." It is unrestricted and may be registered by anyone, from any country.
• .name is the only domain extension specifically designed for personal use. It is commonly used for easy to remember e-mail addresses and personal web sites that display photos or personal information about an individual.
• .co.uk is the country code for United Kingdom. The .co portion of the extension indicates the domain name is for commercial purposes (similar to a standard .com extension). It is unrestricted and may be registered by anyone, from any country.
• .org.uk is the country code for United Kingdom. The .org portion of the extension indicates the domain name is for an organization. It is unrestricted and may be registered by anyone, from any country.
• .me.uk is the country code for United Kingdom. The .me portion of the extension indicates the domain name is for an individual. It is unrestricted and may be registered by anyone, from any country.
• .de is the country code for Germany. It is unrestricted and may be registered by anyone, from any country. If you are not a resident and citizen of Germany, the Administrative Contact for this domain name registration will automatically be assigned Network Solutions' German proxy contact information.
• .eu is the country code for the European Union. Registration of .eu domain names requires registrants to meet one of the three eligibility requirements: have a registered office, central administration or principal place of business within the European Community; have an organization established within the European Community without prejudice to the application of national law; or be a natural person resident within the European Community. Alternatively, you can secure the use of a .eu domain name by using Network Solutions .EU Registration Service. Network Solutions Europe, LLC is the registrar for all .eu domain names.
• .be is the country code for Belgium. It is unrestricted and may be registered by anyone, from any country. YouTube has used it for YouTu.be, for instance.
• .cn is the country code for China. It may be registered by businesses, organizations and sole proprietorships from any country.
• .com.cn is the country code for China. The .com portion of the extension indicates the domain is for commercial purposes (similar to a standard .com extension). It may be registered by businesses, organizations and sole proprietorships from any country.
• .net.cn is the country code for China. The .net portion of the extension represents the word "network", and is generally used by internet infrastructure providers. It may be registered by businesses, organizations and sole proprietorships from any country.
• .org.cn is the country code for China. The .org portion of the extension indicates the domain is for an organization. It may be registered by businesses, organizations and sole proprietorships from any country.
• .cn Regional names. There are 34 regional .cn extensions available, for example, .bj.cn. The .bj portion of the extension represents Beijing and the .cn represents China. These extensions may be registered by businesses, organizations and sole proprietorships from any country.
• .tw is the country code for Taiwan. It may be registered by businesses, organizations and sole proprietorships from any country.
• .com.tw is the country code for Taiwan. The .com portion of the extension indicates the domain is for commercial purposes (similar to a standard .com extension). It may be registered by businesses, organizations and sole proprietorships from any country.
• .org.tw is the country code for Taiwan. The .org portion of the extension indicates the domain is for an organization. It may be registered by businesses, organizations and sole proprietorships from any country.
• .at is the country code for Austria. It is unrestricted and may be registered by anyone, from any country.
• .com.mx is the country code for Mexico. The .com portion of the extension indicates the domain name is for commercial purposes (similar to a standard .com extension). It is unrestricted and may be registered by anyone, from any country.
• .co.nz is the country code for New Zealand. The .co portion of the extension indicates the domain name is for commercial purposes (similar to a standard .com extension). It is unrestricted and may be registered by anyone, from any country.
• .net.nz is the country code for New Zealand. The .net portion of the extension represents the word "network", and is generally used by internet infrastructure providers. It is unrestricted and may be registered by anyone, from any country.
• .org.nz is the country code for New Zealand. The .org portion of the extension indicates the domain name is for an organization. It is unrestricted and may be registered by anyone, from any country.
• .gs is the country code for the South Georgia & South Sandwich Islands. It is unrestricted and may be registered by anyone, from any country.
• .tc is the country code for the Turks & Caicos Islands. It is unrestricted and may be registered by anyone, from any country.
• .ms is the country code for Montserrat. It is unrestricted and may be registered by anyone, from any country.

For a complete list, check out the Wikipedia entry for Top Level Domains.