My article is on readwriteweb. I am glad to see there, thanks to Richard MacManus for his editing and creating readwriteweb.
As the connection speed of the internet has increased, the demand for web related services has also increased. After the Web revolution, peer-to-peer networks evolved and currently have a number of different usages - instant messaging, file sharing, etc. Some other revolutionary ideas are still in research. People want to use peer-to-peer in many different applications including e-commerce, education, collaborative work, search, file storage, high performance computing. In this series of posts, we will look at different peer-to-peer ideas and applications.
For the rest you can visit
P2P: Introduction and Real World Applications