Method of replicating data between computing devices which each use local clocks

1. A method of replicating data stored on a mobile telephone by copying that data to a first computing device, in which the data is stored on the first computing device and made available to other devices by the first computing device, in which the first computing device determines whether data that is time stamped by a second computing device, which is the mobile telephone, using a clock running on the second device, is to be replicated or not comprising the steps of:

(a) the first computing device comparing the time stamp from the second computing device against a time signal from its own local clock to determine a delta and using that delta to deduce the correct delta to apply to time stamps associated with later data from the second computing device; and

(b) the first computing device taking sole responsibility for determining whether or not that later data from the second computing device is to be stored on the first computing device and made available to other devices by the first computing device.

2. The method of claim 1 in which the local clock of the first computing device is set to an absolute, externally derived time.

3. The method of claim 1 in which the delta deduced by the first computing device assumes that the local clock in the second computing device is drifting in a linear manner.

4. The method of claim 1 in which, if a deliberate time adjustment to accommodate a change of time frame is made to the local clock on the second computing device, then the second computing device stores a record of this time adjustment and provides it to the first computing device.

5. The method of claim 4 in which the second computing device alters one or more time stamps stored on it by the amount of the deliberate time adjustment so that the time stamps remain correct in the new time frame.

6. The method of claim 1 in which the first computing device uses its knowledge of the correct deltas relative to its own clock in order to apply correctly a time dependent arbitration rule to determine which of several inconsistent data replication requests it should action.

7. The method of claim 1 in which the time stamp applied by the second computing device is outside of a database record containing the data to be replicated.

8. The method of claim 7 in which the time stamp resides in a change log which includes only the minimum data needed to identify a change to data.

9. The method of claim 1 where the data is contacts data.

10. The method of claim 1 where the data is personal data.

11. The method of claim 1 where the data is presence data.

12. The method of claim 1 where the data is e-mail data.

13. The method of claim 1 where the data is calendar data.

14. The method of claim 1 where the data is picture data.

15. The method of claim 1 where the data is ringtone data.

16. The method of claim 1 where the data is games data.

17. The method of claim 1 where the data is document information.

18. An apparatus, comprising:

a first computing device capable of replicating data stored on a mobile telephone by copying that data to a first computing device, in which the data is stored on the first computing device and made available to other devices by the first computing device and having sole responsibility for determining whether or not data that is time stamped by a second computing device, which is the mobile telephone, using a clock running on the second computing device, is to be stored on the first computing device and made available to other devices by the first computing device;

wherein the first computing device can compare the time stamp from the second computing device against time signals from its own local clock to determine a delta and use that delta to deduce the correct delta to apply to time stamps associated with later data from the second computing device.

19. The apparatus of claim 18 , wherein said first computing device comprises a server and the second computing device acts as a client of that server.