It is. It's a common misconception that peer-to-peer is only about making the handshake symmetrical. Equal contribution of resources is the important thing. In the case of most peer-to-peer technologies, this contribution is in bandwidth, storage space, and tiny routing computations. In the case of seti@home, the contribution was cpu cycles.
Look at the 2 images on the right :) Seti@Home nodes connect only to the main server. They never see or hear anything about other nodes either. If the servers died the network would die.
But I second the Folding@Home prompting - a great cause!
