The Tube could get access to WiFi following backing from London Mayor Boris Johnson. Last month saw the announcement that London would get total WiFi coverage before the 2012 Olympics, and adding WiFi to the underground network could help ensure access is available everywhere. Speaking at the State of London Debate, the mayor said he was in favour of making technological progress if it can be done.
Whether there will be interest from WiFi operators such as The Cloud who will be operating the London-wide network will have to be seen. Running networks underground causes various problems and has been mooted for several years but the high costs of implementing such a system has meant that some projects have never taken off. In 2008 TFL tendered for a trial of mobile phone services on the Waterloo & City line, but the market didn't come up with a technically viable solution.
With WiFi available at stations, this would allow users to make calls using Voice over IP providers and indeed, iPhone 4 users could even make FaceTime calls which currently require a WiFi connection to work. The most common use will likely be for web browsing or e-mail, allowing people to keep working on the tube as they send and receive e-mails when arriving at stations.