Turn off 3G?

John Jason

Android Enthusiast
I have a MyTouch 3G with Andoid 2.2.1. I have a limited data plan (30 MB) because at home and at school I can connect to wifi. Yet the phone continually uses 3G in spite of the fact that it is connected to wifi and the wifi icon is in the panel alongside the 3G icon.

Is there a way to force it to use only wifi?