A data replication system and method. The method and apparatus provides for an efficient means of replicating data over a network in the form of a file between two individuals, or within defined groups of individuals, using a variety of devices to access the Internet, including computers, personal data assistants ("PDA"s) and wireless devices. A group is formed through an exchange of invitation, acceptance, and welcome messages. A group member designates a replication directory on the group member's computer. Files placed in the directory are replicated and stored in the replication directory of each of the other members of the group. Any change to a replicated file causes a message by one member to be sent to all other members. Changes are conveyed via patches that represent the changes made to a replicated file. Replicated files are saved without replacing previous versions of the replicated file. The group formation and file replication processes are accomplished using existing network protocols.