I just bought an audiovox ppc 4100, but t-mobile can't connect my phone to the internet even though i purchased the unlimited internet plan. I was heard that you can change the internet settings to make the phone connect to the internet using t-mobile. Could someone please explain to me step by step how to get connected to the inter net using t-mobile.

I had the same problem when i visited Asia.
I don't know if u have tried this, but here's what i did while in Asia, and it worked gr8.
Tap on the "signal bar" (start< signal bar< vol & date)
In Connectivity, LH bottom corner, tap on "Settings"
Under Connections, go to "Advanced"
Connections->Advanced-> Tap on "Select Networks"
under Network Management, u will c 2 drop down menu's, in both select "GPRS Connection"
Now follow the following procedure for both:
Under each Menus u'll c the edit button,
Tap "edit"
GPRS Connection -> tap " proxy settings"
Select "This network...Internet"
Unselect "This network uses....internet"
Save ur settings and ur done!

This worked for me, so good luck!
Mannu

WELL lets see the settings are

enter name for the connection
gprs connection

select a modem
cellular line (GPRS)

select next

access point name:
wap.voicestream.com

select advances

choose use server assigned ip address

select ok then chose finish