You can use the Nokia 6310i as
- CSD modem,
- HSCSD modem and
- GPRS modem.
For this you need modem scripts, which you write yourself or you use existing scripts from other people
or you use an application, which handles everything for you.
I personally prefer the more 'manual' solution with the scripts.
Existing scripts for Nokia 6310 and explainations you can find at: http://www.taniwha.org.uk
If money doesn't matter, you can buy this software: http://www.novamedia.de/pages_e/e_mhs_mac_2g.html
They offer a test software, which does support the slow CSD access only.
You can write your own scripts with the Modem Scipt Generator: http://www.doorsinternet.com/MSG
Nokia 6310i and iSync are incompatible,
but address book works well for sending and receiving SMS messages and for dialing outgoing and showing incoming calls via Nokia 6310i.
The only problem is, that you have to reconnect with the phone again after powerbook wakes up from sleep (with the bluetooth connect/disconnect button in address book).
Even the last bluetooth firmware update from Apple doesn't fix this problem.
If someone has a solution for this problem, I'm very interested, please post here or send me PM.
For overall bluetooth stability between Mac and phone it is important to have the newest Firmware of Nokia 6310i. Check version with '*#0000#'.
V5.50 or V5.51 are the most actual versions.