Thanks God, now I can [en:iSync]!!!
As someone probably remember, I switched from an [en:Nokia E70] to a [en:Sony Ericsson W950i].
In the beginning, it was not possible to synchronize my [en:iBook] with my new smarth-phone because of a "strange" implementation of the [en:SyncML] protocol on Sony Ericsson/UIQ 3.0 phones.
A lot of people has tried to figure out how to do it (Google for it), failing! But now [en:SonyEricsson] has finally released the relative plugins:
Update 15th August 2007: BTW, the plugins (I tested on only the one for W950i) doesn't synchronize Tasks (Todos). I really don't know why ( :?: ). But it's already a good lip ahead.