South African transportation officials are taking advantage of social media to build buzz around the new Gautrain Rapid Rail Link being built in the Johannesburg metro region.

About 200 Twitter followers and more than 2,700 Facebook fans were invited for a tour and test ride a couple of weeks ago.

This “tweetup” (named #tweetuponrails by Gautrain Twitter followers) was reportedly the largest in South Africa to date, and resulted in an explosion of online publicity for Gautrain. The guests tweeted from their mobile devices and uploaded photos and videos in real time during their visit, and #tweetuponrails became a trending topic on Twicsy.

Within hours of the event, blog entries, Flickr and Picasa photo albums, YouTube and Zoopy videos were published.

Photos, blogs and videos of the event can also be seen on Gautrain’s Facebook fan page.

The high speed rail link is currently under construction and its first phase will be completed in time for the World Cup in June. The system will eventually connect downtown Johannesburg, several satellite cities and the airport. Trains will reach maximum speeds of 160-180 kilometers per hour.