All the info you need is here: http://www.taniwha.org.uk (ross barkman’s home page).
Firstly download the vodafone scripts (scroll down I used the link (Nokia 3G scripts). Unzip the file and copy the three CIS files into /Library/Modem Scripts)
Now link your phone to the mac using the bluetooth wizard (make sure you select the use my phone as a modem checkbox on the last page)
Finally you will need the access point info again ross is there for us http://www.taniwha.org.uk/gprs.html scroll down. I am using o2 so the details are user faster password web AP mobile.o2.co.uk. THere is some info about SMTP and so forth but as I use gmail I have not used that.