Two supposedly new approaches to distributed computing have emerged in the past few years, both claiming to address the problem of organizing largescale computational societies: peer-to-peer (P2P) [15, 36, 49] and Grid computing [21]. Bot

P2P (Peer To Peer) is when multiple computers think collectively towards a shared objective. Computer programs that use less central servers and rely on a collection of computers such as Gnutella, distributed media streaming, networks of DCC based I