The data plan is unlimited so does it really matter?
Isn't it obvious that the OP does not, or will not, have an unlimited data plan from his question? It was to me anyway.
I would also assume that he does not want to use 3g data, regardless of whether wifi is connected or not, UNLESS he specifically turns on 3g data for a limited time.
Ideally, one would be able to turn 3g data to be off by default and have a program which would allow one to temporarily turn on 3g data conditionally constrained with options such as "on for one hour" or "on until I use 5 mb" or "warn me when I go over 10 mb and shut off when I reach 15 mb.
If you want 3g totally off for a given period of time then turn off:
Menu => Settings => Wireless & network settings => Mobile network settings => Data enabled
Thank you for the helpful information. I have a different phone, but I will look for a similar setting. I also have an Android phone (Fascinate, on Verizon atm) and will be switching to another carrier without unlimited data plan (Page Plus, I'm thinking).
I used to have a no-data plan like you.. (Switzerland) And I've been using APNdroid from the market (free and simplest to use!).. There's only one button to press on this app, so don't worry to get lost!
It stops all the apps and browser to connect to the web, but you get your phone calls without any trouble.. once you turn on your wifi, you'll be able to surf through internet.
It automatically enables Internet whenever wifi is on? That sounds GREAT! Thank you!