With some companies setting time limits - measured in hours - for responding to e-mail, the fear is not totally irrational. Luckily, using the Net while on the move is not the challenge it once was.
Most Internet users really only need two of the network's services when they are away from the office or their home computers: e-mail, and access to the World Wide Web. The most obvious mobile Internet tool, the laptop computer, can handle both. At a basic level, any computer with a modem can use the Internet, and good-quality modems are cheap. It's just a question of installing Internet software on the computer, packing a clean shirt and socks, and hitting the road.
External modems, though good value, are not the neatest solution to the problem of staying connected. They can be bulky, and rely on external power supplies and several cables. A more expensive but better alternative is the PC Card (formally PCMCIA card) modem. This credit-card device costs perhaps 50 per cent more than a "desktop" modem, but needs no cables other than a lead for the phone line. Most current laptops have PC Card slots, and modem manufacturers, including US Robotics, Pace, Psion and TDK, sell the cards. Some even come with phone plugs, and approval, for use in other European countries.
Even this plug can be an unexpected hurdle. Modern phone systems can have special sockets that a modem's plug will not fit; if it does fit, and the phone system is digital, there is a good chance that the phone system will blow up the modem. In an office, the safest method is to plug the modem into a dedicated modem line or, failing that, a socket used by a fax.
Hotels are more difficult: trailing phone wires over the reception desk does little for decorum, and less for privacy. Some of the larger and more enlightened hotel groups provide modem sockets, and smaller hotels may have an ordinary analogue phone system. As often as not, however, hotel phones are wired directly into the wall, and the only way to connect a modem is to take to it with a screwdriver and bulldog clips.
The digital mobile phone - on Orange, One 2 One or GSM - offers a far less Heath Robinson approach. PC cards are made specifically to work with mobile phones, and have the added advantage of avoiding expensive hotel call charges. The cards can also send and receive faxes, which is especially helpful when combined with a service that stores faxes for collection later. Vodafone and Orange both offer this.
Mobile adaptors are slower than modems, with a top speed of 9600bps, and at around pounds 300 they are also more expensive than a modem. On the plus side, they work anywhere where there is network coverage, including overseas for Cellnet and Vodafone. Cards such as Pace's Smartcard GSM are coming on to the market; these support both mobile connections and faster, land- line access.
Mobile operators are working on faster access for data across their networks. Orange is working on a service that, it claims, will offer ISDN-style speeds. In the meantime, Internet service providers have teamed up with mobile operators to give cheaper calls. Orange subscribers can dial Demon and Pipex at Orange to Orange rates, and calls to Pipex from Vodafone and Cellnet are 20 per cent cheaper than standard mobile calls.
Access to the Net will become easier still with the new generation of hand-held computers. Organisers, or "personal digital assistants" (PDAs), have been limited until now by relatively poor communications and slow processors. Nor were their small, mono screens terribly good for browsing the Web. Manufacturers have reacted by including e-mail and Web software with their PDAs. The Nokia 9000 goes a step further, even including a mobile phone in the casing.
Psion offers Internet software and an external PC card adaptor for its popular Series 3c palm top, and Apple's latest Newton, the MessagePad 2000, is a capable device for using the Net. Computers using Microsoft's Windows CE operating system for hand-held PCs also support the Internet; Philips' CE-based computer has a modem built in. US Robotics is also working on a new, Net-compatible version of its Pilot PDA.
Even smaller devices are round the corner. In the US, Internet companies already offer e-mail to pager gateways for people who just have to read their messages in meetings. Similar systems make use of digital mobile phones' short message services. You can already e-mail an Orange phone via the company's Web site. Messages are limited to a dozen or so words; anyone who wants to communicate this way would do well to rediscover the virtues of brevity, telegram style.