There are few new things "under the sun". We all build on the past. Peer-to-peer computing has evolved out of standard client/server computing and distributed computing. The availability of cheap high performance computers, access to the Internet and the Web and increasing network bandwidth has enabled the growth of this evolution.
Lots of interesting things are happening in the peer-to-peer realm. Software like Gnutella suggests a direction where information can be published on a network and never suppressed. This is an idea that is both wonderful and horrible. The Scientologists would not be able to sue to suppress their critics and those who publish the comical documents given to "high level clears". But true intellectual property (e.g., engineering and scientific information) could also be published and never recovered or suppressed.
This web page is the start of a set of links to topics on peer-to-peer and distributed computing issues. This is a vast area and should eventually include Jini, JavaSpaces, and the peer-to-peer protocols.
People tend to abuse shared resources that they don't have to pay for in some way (this is the "Tragedy of the Commons"). This is a problem for peer-to-peer networks, where a minority of users provide the resources. This is a speculative essay that suggests a way to encourage the general user base of a peer-to-peer network like a Gnutella music sharing network to provide resources.
The problem of the "Tragedy of the Commmons" is explicitly addressed
Project JXTA is an open source project that is exploring distributed computing protocols for peer-to-peer computing. The project was originally started by Bill Joy and Mike Clary at Sun Microsystems.