A social network service focuses on building online communities of people who share interests and/or activities, or who are interested in exploring the interests and activities of others. Most social network services are web based and provide a variety of ways for users to interact, such as e-mail and instant messaging services. Social networking has encouraged new ways to communicate and share information. Social networking websites are being used regularly by millions of people.

Many of these services launched for "social" reasons, but have application in the educational community.  As with any web application, which is technically publishing, security issues are paramount, especially where children are concerned.   As long as security measures are in place -- many of which are not with default functionality -- teachers can integrate these tools into the classroom.

Facebook (www.facebook.com)

Facebook is a global social networking website that is operated and privately owned by Facebook, Inc. Users can add friends and send them messages, and update their personal profiles to notify friends about themselves. Additionally, users can join networks organized by city, workplace, school, and region. The website's name stems from the colloquial name of books given at the start of the academic year by university administrations with the intention of helping students get to know each other better.

Twitter (www.twitter.com)

Twitter is a free social networking and micro-blogging service that enables its users to send and read messages known as tweets. Tweets are text-based posts of up to 140 characters displayed on the author's profile page and delivered to the author's subscribers who are known as followers. Senders can restrict delivery to those in their circle of friends or, by default, allow open access. Users can send and receive tweets via the Twitter website, Short Message Service (SMS) or external applications.

Second Life (www.secondlife.com)

Second Life (SL) is a virtual world developed by Linden Lab that launched in 2003 and is accessible via the Internet. A free client program called the Second Life Viewer enables its users, called Residents, to interact with each other through avatars. Residents can explore, meet other residents, socialize, participate in individual and group activities, and create and trade virtual property and services with one another, or travel throughout the world, which residents refer to as the grid. Second Life is for people aged 18 and over, while Teen Second Life is for people aged 13 to 17.  Many organizations have created islands on Second Life for virtual meetings, classrooms, and events. For example, you can visit EDTECH Island which offers free resources and space for all teachers and faculty. Or visit the Illinois Math and Science academy virtually.