The London Transit Authoritytfl.gov.uk is testing a new system for its rail commuters by Twitter. Essentially you can sign up and receive customised tweets or alerts regarding your travel plans. You can also specify the information you want to receive - if you regularly catch a train to or from work it would be a rather handy tool to let you know of any delays as opposed to finding out on the platform.
Interesting how social media platforms are going from just being social to now being more applicable to different aspects of our world. With the way many train systems operate in the world your Twitter feed could not only be hugely beneficial and save you engaging in unproductive time disruptions, delays and cancellations