Well, only because we love you ...
My friend, I'm sorry to say, but you cannot,
mark my words, cannot, use your mobile as a modem on linux.
See, it's all about drivers
. Nokia shipped drivers with the phone which you installed on Windows. It is these drivers which allow your phone to talk
to Windows. Sadly, I seriously doubt that similar drivers should exist for Linux. What you can do, however, is to buy an external serial modem, which has somewhat greater
chances to work with Linux. I bought one for about Rs.1700 from my local vendor.