I love my Nokia 6120c. Now I have a new trick - internet access on my Macbook, using the phone's net connection.
It's trivial. Don't google, don't download scripts, don't do anything hard. Just go to System Preferences -> Network, choose Bluetooth, enter the Access Point Name under Telephone Number, and click Set Up Bluetooth Device. Leopard has the scripts already - just select Nokia, 3G.
To get your Access Point Name, Username and Password, look in your phone's settings. For Three Mobile in the UK, it's "three.co.uk", blank username/pass.
It Just Works.