Several stations on the T will have Wi-Fi access: Park Street, Downtown Crossing, Government Center, and State Street (and tunnels connecting stations) will have Wi-Fi access provided by InSite. The city may extend the network to the whole system. I can't see laptops in use in those environments, but VoIP Wi-Fi phones, handhelds, and unknown portable Wi-Fi appliances are all candidates. There's no mention of the cost.