The use of wireless technologies in trains, planes and other modes of transportation has all kinds of implications. Peter Cochrane considers some of them… This all began some months ago by a chance encounter in a hotel lobby in Florida. I was looking to see if there was a public Wi-Fi service available and picked up several signals but none of them turned out to be base stations providing service. This prompted me to discreetly walk around the area with my laptop in hand sniffing for signal sources. It turned out that three laptops were on air and transmitting without, I presume, their owners being aware. The restaurant staff were also using PDAs to take orders linked back to the cash register and kitchen area. I later repeated this experiment on a couple of train journeys in the UK, as well as more hotel lobbies, coffee shops and other public places across Europe and South-East Asia. In fact everywhere I go I see more and more people working on laptops and, whenever I spot a cluster, I take a look-see. With Wi-Fi now being built into almost all new laptops and some PDAs, perhaps I shouldn