In this paper, we present the analysis of a large client-side web trace gathered from the Home IP service at the University of California at Berkeley. Specifically, we demonstrate the heterogeneity of web clients, the existence of a strong and very predictable diurnal cycle in the clients' web activity, the burstiness of clients' requests at small time scales (but not large time scales, implying a lack of self-similarity), the presence of locality of reference in the clients' requests that is a strong function of the client population size, and the high latency that services encounter when delivering data to clients, implying that services will need to maintain a very large number of simultaneously active requests. We then present system design issues for Internet middleware services that were drawn both from our trace analysis and our implementation experience of the TranSend transformation proxy.