Since the Nokia Ngage uses the symbian, can we hack it so we can use the Internet right on it without the required service from the carrier? I am using Cingular which is so stupid that I don't want to pay for their expensive fee....

You have to connect it through your computer's internet connection via bluetooth and a bluetooth adapter for the computer, or if you want to have it away from a computer you have to just pay the fee (or pay as you send/receive data).

You can't have free internet away from the computer using the N-Gage.

And if you don't like Cingular, you can get a SIM card form another GSM/GPRS operator in your area and use their network, instead.