Extensible device synchronization architecture and user interface

A synchronization system, comprising:

• a UI layer, wherein applications are able to register for one or more of a plurality of content types which are supported for synchronization, the registrations allowing the applications to provide UI at the UI layer for configuring the types of content that have been registered for;
• and
• a synchronization engine layer, wherein a handler is invoked when a synchronization is started and the handler is responsible for synchronizing content based on a user's settings.

A synchronization system, comprising:

• a device capabilities store which maintains information about a device's capabilities, such that data that is to be synchronized to the device may be altered to be appropriate for the device;
• and
• a user options store which maintains information about user options for the device synchronization process.

A computer-readable medium having computer-executable instructions for performing steps comprising:

• determining if content that is to be synchronized to a device needs to be reduced in size in order to be appropriate for the device;
• and
• determining if the content that is to be synchronized needs to be reformatted in order to be appropriate for the device.