I'd imagine those skilled at using mobile phones, which are essentially small computers that are internet connected via wi-fi: would find it easy enough.
I'm long since retired but it seems to me, based on watching my older grandchildren who effortlessly send texts, browse the internet, watch videos and listen to music while I taxi them around: sometimes they even use their phones to make phone calls. I occasionally take the train into the centre of Glasgow myself and I see a fair number of my fellow passengers sitting holding devices and their fingers and thumbs are flying, so I'd image anyone commuting to work as a passenger could easily check and answer e-mails with even minimal space as long as they have enough to be able to use their phone.
Even I can sit on a train and check the racing results on my phone - so I'd imagine the likes of NS, Jeremy and Prof D could easily 'work' before they get to work.
