Devices as peers
How to integrate sub- PC devices such as cell phones, PDAs or home appliances into the web is not clear. Limited bandwidth, computing power, very small screens, short-lived connections and other physical limitations make such devices a harsh environment for the web. At the same time the unique features of devices, such as portability and high consumer acceptance, give them much promise as either points of access to the Internet or resource providers to the Internet.
There have been many attempts to address these issues, among them Sun's Jini project, most tied together by a futuristic vision of a vast and heterogeneous global network. What peer to peer adds is the notion of running a server on the device, which is required if the device needs to provide information as well as consume it. Since this is a reasonable need, there seems to be a natural call for P2P in this space.