1. In an information processing system, a method for synchronizing a first dataset with at least a second dataset via a communication medium, the method comprising: storing information that is indicative of a first version of user data of the first dataset, wherein the first version was involved in prior use for synchronizing with the second dataset; identifying a change in the second dataset that is new relative to the first version of the user data of the first dataset; via the communication medium, communicating the change in the second dataset and indicating the first version based on the stored information; determining whether user data currently in the first dataset has changed relative to the first version that was indicated in the communicating and indicating step; deciding whether to commit the communicated change to the first dataset based at least in part on the determining step; and committing the communicated change to the first dataset if the communicated change is decided to be committed in the deciding step.