I'm using google sync on my Curve and on my PC, so the calendar on both stay in sync very nicely now. No addresses or tasks yet, but it's free.
I looked at a few other subscription services, but balked at signing up for yet another subscription charge (seems that life is filled with these nowadays!). I've been watching Funambol, and getting the impression that it may finally be "ready for prime time". If so, how much difference is there between ThinkPost and something like ScheduleWorld, beyond the fact that ScheduleWorld is free?