Several commentators have weighed in on this subject. Obviously, in order to be mobile, the device must have a smaller screen than a desktop computer. A compromise somewhat along the lines of the Palm Pilot can combine mobility with a decent-sized screen. So this latest round of angst towards the smaller screen is based on the principle that the vendor can't adequately predict what you want to do and when you want to do it, or how you want to use your device, what you will use it for and when you want to use it. Well User modeling and anthropology are essentially the same thing but coming at the problem from two different angles.
Anthropology is by and large, the study of how people live.
If you study how people live then you can better understand how technology can help them and what effect it will have on their lives. In order to design effective small wireless devices, you have to understand people. The devices are by their very nature Modal devices. So you are stuck with a modal design. In order to solve the puzzle you have to figure out which modes will best suit your Users.