Do you know the difference between domain squatting and domain investing? The two are often confused, which is a frustration to domain investors who definitely do not want to be thought of as domain squatters. The biggest difference between the two groups is that one group, the domain squatters, purposely register trademarked domain names, while the other group, domain investors, register non-trademarked domains they think will be a good investment.
It is disappointing to find that your perfect domain is already taken by someone else, but just because someone else owns the domain and isn't using it doesn't make them a domain squatter. It just means that someone else also thought that domain was a good one and registered it before you. Most domain investors own hundreds, if not thousands of domains. You certainly won't see a website on each one, especially because many of them are making money off of the links you often see in lieu of a website. The good news is, if the domain you want is owned by a domain investor as opposed to someone who is actually using it for a website, you still have a chance of owning that perfect domain.
If you are interested in trying to buy a domain that is already owned, you can find the owner via a Whois lookup. ICANN, the non-profit regulatory body that is responsible for managing the domain name system, requires each domain owner's contact information to be placed into a publicly available Whois database. You can use this database to contact the owner to see if he or she is willing to sell. Keep in mind that the owner may be looking for a high sale price depending on the domain. Some domains have sold for millions of dollars - the most expensive domain sale was $30 million for Voice.com.