They have left Zimbabwe. Friends, family members and people I have worked with.

Left: Zimbabwean Facebookers have set up sixteen Kirsty Coventry fan groups.

Over the last ten years I have been to the airport many heartbreaking times to say good bye to them as they jetted off to destinations all over the world. Then there are those who I never said good bye to. Those who just faded into the crowd- never to be seen again- until I signed up to Facebook and started meeting them all again, one by one.

Facebook is arguably the most popular social networking site in the English speaking world. Over 250 thousand people sign up to it every day. It is estimated that there are over 75 million active users on the site (WikiAnswers). With numbers that huge the chances of finding people you know are vastly increased.

With a world where people move countries and cities more and more, this sort of online networking becomes more relevant.

There was a time when after school most of the friends you grew up with remained in the same town as you. So you could stay in touch with your circle of allies quite easily.

Right: There are at least sixteen Kirsty Coventry fan clubs on Facebook.

The economic and political challenges in Zimbabwe over the last ten years, along with the opening up of international career opportunities, have changed all that. Young people have left Zimbabwe in their hundreds of thousands. It is estimated that there are over four million Zimbabweans living outside the country. So the problem I have- that of a diminishing social circle- is shared by millions.

Enter Facebook, LinkedIn, MySpace and similar social networking sites and all my friends, wherever they are in the world, are part of my social circle again. But how does it all work?

When you sign up for a social networking site, like Facebook, you are able to link up to any one else who has signed up on the site. If you are looking for an old friend you simply do a search for them and if they are listed you can make a request to be included in their list of friends. Your friend can then choose to accept the request- or deny it.

Once you are included in someone’s list of friends you can view their profile, which includes information about who they are, where they currently live, what work they do etc. You can also share photos and videos, chat with them in real time if they are online at the same time as you or leave them a message if they are not.

You can also set up a group that brings together people that share a similar passion . For example, there are at least sixteen Kirsty Coventry fan clubs on Facebook. You can also become part of a network, which is a geographical grouping of people on the site.

In other words, an online social network enables you to keep up with the people that matter in your life. Families that live in different cities can constantly update each other. Friends can share jokes, news items, videos and life in general. You can even send a virtual gift to someone on their birthday, which you are prompted to remember by a feature on the website.

Other Zimbabwean groups on the site include ones that discuss music, Christianity, politics. There are also high school and university alumni groups and new groups are created every day.

Left: There are 24,919 people in the Zimbabwe network on Facebook.

And how many Zimbabweans are on Facebook? That’s difficult to say. The Zimbabwe network on the site has just under 25,000 people. There will be some Zimbabweans who are on Facebook but not part of that network so this is not an all inclusive figure.

Just this morning, I had conversations on Facebook with two friends that I last saw at primary school. That was almost twenty years ago. One of them is working in South Korea. Another is studying in the United States. All in all I have met over 100 long lost friends and acquaintances online in the last year.

The celebrated high school reunion and it’s similarly famous college reunion now happen on the Internet every single day.