Facebook founder Mark Zuckerberg

Mark Zuckerberg, founder of Facebook, speaks to advertising partners about targeted advertising.

AP Photo/Craig Ruttle

The World Wide Web is a powerful tool. It allows people to communicate and connect in ways that simply weren't possible a few decades ago. You can chat with friends on the other side of the planet, sharing photos and videos while you catch up. With the Web, you may be able to track down an old friend whom you've not seen in years. You can make new friends or even find your soul mate.

Online social networking sites are some of the most popular online destinations right now. These sites tend to package services together in an organized and attractive way so that users can leverage the Web to make connections with others. There are hundreds of social networking sites. They range in size from enormous -- like Facebook and MySpace -- to smaller sites aimed at a specific niche -- like Ravelry, a social networking site for people who like to knit. These sites can bring people closer together while being miles apart.

They can also be lucrative projects. Mark Zuckerberg launched Facebook in 2005 -- by 2008 he made the list of the 400 richest Americans with a net worth of $1.5 billion [source: Forbes]. The husband-and-wife team of Michael and Xochi Birch started the social networking site Bebo in 2005 as well. Three years later, AOL purchased the site and the couple netted $600 million [source: Mashable]. A quick glance at the history of online social networking sites will uncover several other remarkable success stories, too.

Just because there are a lot of social networking sites on the Web doesn't mean the well is dry. In fact, someone may come up with a brilliant idea and implementation of a social networking site tomorrow and become the next great innovator of Web 2.0. That someone might be you. But what does it take to start a social networking site?