Could be a useful technology as long as the "the users' computers are automatically connected to the SNCF web site" part is secured properly! Looks like a another great opportunity for the hacker set to me...
Speaking of USB, I was comparing a couple of options for a school and noticed one was getting a Dell box that mentioned "Built-in Wireless USB capability" What the heck is that? It already has an 802.11g Mini card. I don't see what USB has to do with 'wireless' capability.