With the iPad looming, folks are going to be using more electronic devices than ever. And the US Patent & Trademark Office has granted a patent (number 7,689,920) for a method of synchronizing three or more electronic devices and a computer system for implementing that method.

In one exemplary method of synchronizing three or more electronic devices, said method comprises: a) selecting at least one category of record for synchronization; b) storing an original value and a changed value of each changed record from a selected record category; c) establishing an electronic connection between at least two devices; d) comparing the records of the selected record categories; e) determining any changed record; f) identifying the updated device with the changed record having an original value the same as the value of the record in the other previous device; and g) changing the value of the record in the previous device to the changed value. The inventors are Jean-Marie Hullot, Bertrand Guiheneuf, Laurent Cerveau and Eric Noyau.

Here's Apple's background and summary of the invention: "The present invention relates to a method of synchronizing three or more electronic devices and a computer system for implementing that method. In particular but not exclusively those electronic devices may include personal computers, computer servers, personal digital assistants and mobile telephones. Moreover, synchronization occurs for a selected category of record which may include, but not exhaustively, computer programs and data comprising calendar, email, audio, graphic, notes and personal information such as contact lists, names, addresses, telephone numbers, e-mail addresses etc.

"At present many consumers have many such electronic devices. Typically a consumer may have a personal computer at work, one at home, a notebook or personal digital assistant and a mobile telephone. Moreover, it is very common to have the same record on more than one device. However, it is a rare occurrence for all of those devices to be present simultaneously. Thus, whenever a change occurs to a record, that record must be changed on each of the electronic devices. This leads inherently to errors being introduced not only when effecting the change but also ensuring that all of the devices have been updated.

"It has been proposed to provide a method of synchronization between two devices. The proposal achieves synchronization by comparing the selected records between the two devices and updating the previous device. However, although it has been desired to synchronize more than two devices, it has not been possible due to difficulties encountered such as when not all of the devices are present or when there are conflicting changes which have been effected across each of the devices.

"Certain embodiments of the present invention are directed towards a method of synchronizing three or more electronic devices and a computer system.

"One exemplary embodiment of the present invention relates to a method of synchronisng three or more electronic devices, said method comprising the steps of: a) selecting at least one category of record for synchronization; b) storing an original value and a changed value of each changed record from a selected record category; c) establishing an electronic connection between at least two devices; d) comparing the records of the selected record categories; e) determining any changed record; f) identifying the updated device with the changed record having an original value the same as the value of the record in the other previous device; and g) changing the value of the record in the previous device to the changed value.

"The present invention also relates to a computer system comprising three or more electronic devices and a computer program arrange to implement the method as claimed in any one the attached claims.

"The foregoing method is facilitated, in one exemplary embodiment, through the use of a computer system having a computer program operative on a computer such as one of the Macintosh personal computers from the applicant, Apple Computer Inc. of Cupertino, Calif., USA. More preferably the computer program is operative in the MacOS x version 10.2, known as Jaguar (Registered Trade Mark). Moreover, the computer program is complementary to Mail and Address Book computer applications also available from Apple for full personal information management. The computer program of this particular embodiment is compatible with printing applications and functions.

"In addition, the computer program of this particular embodiment is compliant with standards for calendaring applications such as iCal and vCal and may allow import of data from other applications like Entourage available from Microsoft. Further details can be obtained from http://www.imc.org/draft-ietf-calsch-inetcal-guide. The computer program of this particular embodiment is also compatible with the iTools web service available from Apple in order to share calendar data easily over the Internet.

"In view of the compatibility discussed above and in particular with the operating system, the computer program of this particular embodiment may enable copy and paste with other applications, drag and drop facilities, use of the spellchecker, integration with email applications and integration with address applications for management of personal information."