Sneak is much impressed by London Underground's ETA service, a web-page that can push out train arrival times to owners of wireless PDAs. In beta at present, it covers only the Bakerloo line but nonetheless allows Sneak to decide whether to amble, stroll or pelt down to Picadilly Circus at the end of a busy day. Sneak foresees just one problem. The times when Sneak will really, really, really want to get at ETA's precious data will be during those not-exactly-infrequent episodes when the tube trains all appear to be on holiday, and the platform indicators are up the spout. But, of course, at such a frustrating juncture, Sneak will already be underground, out of radio range, and so Sneak's GPRS-equipped palmtop will be incommunicado. There are, of course, reported plans to bring mobile services to the Tube network. With any luck, these will be limited to the stations, allowing ETA access but sustaining the Tube's considerable advantage over surface lines: namely, that you don't ever have to put up with people bellowing, "I'm on the train. What? No, I'm on the train..."