Some of the ideas presented in this section were developed with two groups with which the author has collaborated in work on nomadic computing and communications. One of these is the Nomadic Working Team (NWT) of the Cross Industrial Working Team (XIWT); the author is the chairman of the NWT, and this working team recently published a white paper on nomadic computing (NWT, 1995). The second group is a set of his colleagues at the UCLA Computer Science Department who are working on an ARPA-supported effort known as TRAVLER, of which he is principal investigator.