A lot of this depends on what type of phone you are using.
If it's an Android, syncing through apps that understand Gmail tools is pretty easy. I pull my Google Calendar into my computers with Korganizer.
If it's a Windows Mobile 6 phone, you are hiking up hill. (I have no experience with the new Windows mobile and have every expectation of maintaining that track record.)
I used to have a Windows Mobile 6 phone; I tried to set up SyncCE
and concluded it was not worth the trouble, since I had no compelling (that is, would cost me money) reason making the sync happen; what I had to sync, I synced with email or with the digital (as in tapping with finger) method.