e PDAs with wireless Internet access. Both the human interface of cellular telephones and the air interface of PDAs and laptops need improvement. But what is most needed is packaged solutions that work when we turn them on. Wireless data will not sell well as long as customers need to order special cables or install anything more complex than a card that shoves into a slot (and even this will be too much for many users). We are in a chicken-and-egg situation where the market is not proven enough for low-cost production of easy-to-use solutions and the hard-to-use solutions are slow- ing market acceptance. This probably will pass, although whether it will take a couple of months or a few years depends largely on the state of the economy and the quality of new interface design offerings. What does the future hold? We should look at two areas: uses of cellular technology that do not involve people and new ways of living a wireless life. Some industry prog- nosticators have realized that there is a fundamental limit to the number of cellular telephones that can be sold and that it is closely tied to the number of people on planet earth. A significant fraction of the people on the planet already have cellular tele- phones. We may expand the market a bit by having people each own two or even a few user terminals. Probably, though, the personal area network (PAN), with a wireless ra- dius of about 10 m, will allow our telephones, laptops, electronic wallets, and who knows what else to link together and share one cellular interface device. No, the real market growth, some say, is to sell wireless devices that have nothing to do with people at all. This is an example of the notion of ubiquitous computing, and one proposed term is invisible mobile. More simply, we are talking about very inexpensive widespread telemetry. Wireless devices could provide unique identification showing where something is located at any time. One proposal suggests that if the devices were cheap enough, one could be attached to each soda bottle du