How long til wireless internet on trains and/or planes is common?

[partygirluk]

Is there any reason why a train couldn't have a wireless hub in it and users who had a laptop + wireless internet card could log on whilst travelling? How difficult would this be to implement?

What about something similar on aeroplanes? I read 6 months ago that "the authorities" were coming to the conclusion that using a mobile phone on an aeroplane did not interfere with the navigational system - playing poker would be a good way to make that 12 hour flight more bearable.