I've been trying to buy tickets for the overnight car ferry from Naples to the Aeolian island of Lipari. It's harder than you'd think. You can buy tickets for the hydrofoil easily enough online, but you can't put the car on one of them (and without the car, there's no easy way up the mountain to where I'm staying). The sporadic car ferry service is operated by Siremar (Sicilia Regionale Marittima), a division of Tirrenia di Navigazione, which is owned by the state. You can go through most of the booking process online, but it comes to an abrupt end just before the point at which you'd do the actual booking. So I rang them up (it's a premium line: 18 cents per minute). They told me their computer was down, and that anyway even though I could book over the phone, to pay I'd have to go to a travel agent. I could find a list of authorised agents on the website.